Heterocyclic compound and organic light-emitting device including the same

ABSTRACT

A heterocyclic compound is represented by Formula 1. An organic light-emitting device includes: a first electrode; a second electrode facing the first electrode; and an organic layer between the first electrode and the second electrode and including an emission layer, wherein the organic light-emitting device includes at least one of the heterocyclic compound.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. application Ser. No. 16/529,327, filed Aug. 1, 2019, which claims priority to and the benefit of Korean Patent Application No. 10-2018-0147692, filed on Nov. 26, 2018, in the Korean Intellectual Property Office, the entire contents of both of which are incorporated herein by reference.

BACKGROUND 1. Field

One or more embodiments of the present disclosure relate to a condensed heterocyclic compound and an organic light-emitting device including the same.

2. Description of the Related Art

Organic light-emitting devices are self-emission devices that produce full-color images, and also have wide viewing angles, high contrast ratios, short response times, and excellent characteristics in terms of brightness, driving voltage, and response speed, as compared to other devices in the art.

An example of such organic light-emitting devices may include a first electrode located on a substrate, and a hole transport region, an emission layer, an electron transport region, and a second electrode, which are sequentially located on the first electrode. Holes provided from the first electrode may move toward the emission layer through the hole transport region, and electrons provided from the second electrode may move toward the emission layer through the electron transport region. Carriers, such as holes and electrons, recombine in the emission layer to produce excitons. These excitons transit (e.g., transition or relax) from an excited state to a ground state, thereby generating light.

SUMMARY

One or more embodiments include a novel heterocyclic compound and an organic light-emitting device including the same.

Additional aspects of embodiments will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments.

An aspect of an embodiment provides a heterocyclic compound represented by Formula 1 below:

In Formulae 1 and 2-1 to 2-7,

-   -   X₁ to X₃ are each independently N or C(R₁₅), wherein at least         one selected from X₁ to X₃ is N,     -   L₁ to L₃ are each independently a substituted or unsubstituted         C₃-C₆₀ carbocyclic group or a substituted or unsubstituted         C₁-C₆₀ heterocyclic group,     -   a1 to a3 are each independently an integer from 0 to 3,     -   Ar₁ to Ar₃ are each independently a group represented by one         selected from Formulae 2-1 to 2-7,     -   Y₁ is O or S,     -   R₁ to R₁₆ are each independently be selected from hydrogen,         deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a         nitro group, an amino group, an amidino group, a hydrazine         group, a hydrazone group, a carboxylic acid group or a salt         thereof, a sulfonic acid group or a salt thereof, a phosphoric         acid group or a salt thereof, a substituted or unsubstituted         C₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀         alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl         group, a substituted or unsubstituted C₁-C₁₀ alkoxy group, a         substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a         substituted or unsubstituted C₂-C₁ heterocycloalkyl group, a         substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a         substituted or unsubstituted C₂-C₁₀ heterocycloalkenyl group, a         substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or         unsubstituted C₆-C₆₀ aryloxy group, a substituted or         unsubstituted C₆-C₆₀ arylthio group, a substituted or         unsubstituted C₂-C₆₀ heteroaryl group, a substituted or         unsubstituted monovalent non-aromatic condensed polycyclic         group, a substituted or unsubstituted monovalent non-aromatic         condensed heteropolycyclic group, —Si(Q₁)(Q₂)(Q₃), —N(Q₁)(Q₂),         —B(Q₁)(Q₂), —S(═O)₂(Q₁), and —P(═O)(Q₁)(Q₂),     -   b3 is an integer from 0 to 3, b4 is an integer from 0 to 4, and         b5 is an integer from 0 to 5,     -   of the groups included in the heterocyclic compound represented         by Formula 1, at least one selected from the substituents R₁ to         R₁₁ of Formulae 2-1 to 2-7 is —Si(Q₁)(Q₂)(Q₃),     -   when Ar₁ is a group represented by Formula 2-7, a1 is 0, when         Ar₂ is a group represented by Formula 2-7, a2 is 0, and when Ar₃         is a group represented by Formula 2-7, a3 is 0,     -   when Ar₁ is a group represented by Formula 2-7, Ar₂ and Ar₃ are         not a group represented by Formula 2-1 and L₂ and L₃ are not a         benzene group, when Ar₂ is a group represented by Formula 2-7,         Ar₁ and Ar₃ are not a group represented by Formula 2-1 and L₁         and L₃ are not a benzene group, and when Ar₃ is a group         represented by Formula 2-7, Ar₁ and Ar₂ are not a group         represented by Formula 2-1 and L₁ and L₂ are not a benzene         group, and     -   a case in which each of Ar₁ to Ar₃ is a group represented by         Formula 2-1 is excluded,     -   at least one substituent of the substituted C₃-C₆₀ carbocyclic         group, the substituted C₁-C₆₀ heterocyclic group, the         substituted C₁-C₆₀ alkyl group, the substituted C₂-C₆₀ alkenyl         group, the substituted C₂-C₆₀ alkynyl group, the substituted         C₁-C₆₀ alkoxy group, the substituted C₃-C₁₀ cycloalkyl group,         the substituted C₂-C₁₀ heterocycloalkyl group, the substituted         C₃-C₁₀ cycloalkenyl group, the substituted C₂-C₁₀         heterocycloalkenyl group, the substituted C₆-C₆₀ aryl group, the         substituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀         arylthio group, the substituted C₂-C₆₀ heteroaryl group, the         substituted monovalent non-aromatic condensed polycyclic group,         and the substituted monovalent non-aromatic condensed         heteropolycyclic group is selected from:     -   deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a         nitro group, an amidino group, a hydrazino group, a hydrazono         group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀         alkynyl group, and a C₁-C₆₀ alkoxy group;     -   a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl         group, and a C₁-C₆₀ alkoxy group, each substituted with at least         one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group,         a cyano group, a nitro group, an amidino group, a hydrazino         group, a hydrazono group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀         heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁         heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy         group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a         monovalent non-aromatic condensed polycyclic group, a monovalent         non-aromatic condensed heteropolycyclic group,         —Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁),         —S(═O)₂(Q₁₁), and —P(═O)(Q₁₁)(Q₁₂);     -   a C₃-C₁₀ cycloalkyl group, a C₁-C₁ heterocycloalkyl group, a         C₃-C₁₀ cycloalkenyl group, a C₁-C₁ heterocycloalkenyl group, a         C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio         group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic         condensed polycyclic group, a monovalent non-aromatic condensed         heteropolycyclic group, a biphenyl group, and a terphenyl group;     -   a C₃-C₁₀ cycloalkyl group, a C₁-C₁ heterocycloalkyl group, a         C₃-C₁₀ cycloalkenyl group, a C₁-C₁ heterocycloalkenyl group, a         C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio         group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic         condensed polycyclic group, a monovalent non-aromatic condensed         heteropolycyclic group, a biphenyl group, and a terphenyl group,         each substituted with at least one selected from deuterium, —F,         —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an         amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀         alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a         C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁         heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀         heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy         group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a         monovalent non-aromatic condensed polycyclic group, a monovalent         non-aromatic condensed heteropolycyclic group, a biphenyl group,         a terphenyl group, —Si(Q₂₁)(Q₂₂)(Q₂₃), —N(Q₂₁)(Q₂₂),         —B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), and —P(═O)(Q₂₁)(Q₂₂);         and     -   —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁),         —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), and     -   Q₁ to Q₃, Q₁₁ to Q₁₃, Q₂₁ to Q₂₃, and Q₃₁ to Q₃₃ are each         independently selected from:     -   hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano         group, a nitro group, an amidino group, a hydrazino group, a         hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a         C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl         group, a C₁-C₁ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl         group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a         C₆-C₆₀ aryl group substituted with a C₁-C₆₀ alkyl group, a         C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed         polycyclic group, a monovalent non-aromatic condensed         heteropolycyclic group, a biphenyl group, and a terphenyl group;         and     -   a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl         group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁         heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁         heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryl         group substituted with a C₁-C₆₀ alkyl group, a C₁-C₆₀ heteroaryl         group, a monovalent non-aromatic condensed polycyclic group, a         monovalent non-aromatic condensed heteropolycyclic group, a         biphenyl group, and a terphenyl group, each substituted with at         least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl         group, a cyano group, a nitro group, an amidino group, a         hydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, and         —Si(R_(a))(R_(b))(R_(c)),     -   R_(a) to R_(c) are each independently selected from hydrogen,         deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a         nitro group, an amino group, an amidino group, a hydrazine         group, a hydrazone group, a carboxylic acid group or a salt         thereof, a sulfonic acid group or a salt thereof, a phosphoric         acid group or a salt thereof, a substituted or unsubstituted         C₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀         alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl         group, a substituted or unsubstituted C₁-C₆₀ alkoxy group, a         substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a         substituted or unsubstituted C₂-C₁₀ heterocycloalkyl group, a         substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a         substituted or unsubstituted C₂-C₁₀ heterocycloalkenyl group, a         substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or         unsubstituted C₆-C₆₀ aryloxy group, a substituted or         unsubstituted C₆-C₆₀ arylthio group, a substituted or         unsubstituted C₂-C₆₀ heteroaryl group, a substituted or         unsubstituted monovalent non-aromatic condensed polycyclic         group, and a substituted or unsubstituted monovalent         non-aromatic condensed heteropolycyclic group, and     -   * indicates a binding site to a neighboring atom.

Another aspect of an embodiment provides an organic light-emitting device including: a first electrode; a second electrode facing the first electrode; and an organic layer between the first electrode and the second electrode and including an emission layer, wherein the organic light-emitting device includes at least one of the heterocyclic compound.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects of embodiments will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings in which:

FIG. 1 is a schematic view of an organic light-emitting device according to an embodiment;

FIG. 2 is a schematic view of an organic light-emitting device according to an embodiment;

FIG. 3 is a schematic view of an organic light-emitting device according to an embodiment; and

FIG. 4 is a schematic view of an organic light-emitting device according to an embodiment.

DETAILED DESCRIPTION

Reference will now be made in more detail to embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. In this regard, the present embodiments may have different forms and should not be construed as being limited to the descriptions set forth herein. Accordingly, the embodiments are merely described below, by referring to the figures, to explain aspects of embodiments of the present description. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Expressions such as “at least one of,” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list.

According to an aspect of an embodiment of the present disclosure, a heterocyclic compound is represented by Formula 1:

In Formulae 1 and 2-1 to 2-7,

-   -   X₁ to X₃ may each independently be N or C(R₁₅), and at least one         selected from X₁ to X₃ may be N.

In Formula 1, L₁ to L₃ may each independently be a substituted or unsubstituted C₃-C₆₀ carbocyclic group or a substituted or unsubstituted C₁-C₆₀ heterocyclic group.

In one embodiment, L₁ to L₃ may each independently be selected from:

-   -   a benzene group, a pentalene group, an indene group, a         naphthalene group, an azulene group, a heptalene group, an         indacene group, an acenaphthalene group, a fluorene group, a         spiro-bifluorene group, a spiro-benzofluorene-fluorene group, a         benzofluorene group, a dibenzofluorene group, a phenalene group,         a phenanthrene group, an anthracene group, a fluoranthene group,         a pyrene group, a chrysene group, a naphthacene group, a picene         group, a perylene group, a pyrrole group, a thiophene group, a         furan group, a silole group, an imidazole group, a pyrazole         group, a thiazole group, an isothiazole group, an oxazole group,         an isoxazole group, a pyridine group, a pyrazine group, a         pyrimidine group, a pyridazine group, a triazine group, a         benzofuran group, a benzothiophene group, a benzosilole group, a         dibenzosilole group, a quinoline group, an isoquinoline group, a         benzimidazole group, an imidazopyridine group, and an         imidazopyrimidine group;     -   a benzene group, a pentalene group, an indene group, a         naphthalene group, an azulene group, a heptalene group, an         indacene group, an acenaphthalene group, a fluorene group, a         spiro-bifluorene group, a spiro-benzofluorene-fluorene group, a         benzofluorene group, a dibenzofluorene group, a phenalene group,         a phenanthrene group, an anthracene group, a fluoranthene group,         a pyrene group, a chrysene group, a naphthacene group, a picene         group, a perylene group, a pyrrole group, a thiophene group, a         furan group, a silole group, an imidazole group, a pyrazole         group, a thiazole group, an isothiazole group, an oxazole group,         an isoxazole group, a pyridine group, a pyrazine group, a         pyrimidine group, a pyridazine group, a triazine group, a         benzofuran group, a benzothiophene group, a benzosilole group, a         dibenzosilole group, a quinoline group, an isoquinoline group, a         benzimidazole group, an imidazopyridine group, and an         imidazopyrimidine group, each substituted with at least one         selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a         cyano group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a         cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a         cyclopentenyl group, a cyclohexenyl group, a phenyl group, a         biphenyl group, a terphenyl group, a pentalenyl group, an         indenyl group, a naphthyl group, an azulenyl group, a heptalenyl         group, an indacenyl group, an acenaphthyl group, a fluorenyl         group, a spiro-bifluorenyl group, a benzofluorenyl group, a         dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl         group, an anthracenyl group, a fluoranthenyl group, a pyrenyl         group, a chrysenyl group, a naphthacenyl group, a picenyl group,         a perylenyl group, a pentaphenyl group, a hexacenyl group, a         pentacenyl group, a rubicenyl group, a coronenyl group, an         ovalenyl group, a pyrrolyl group, a thiophenyl group, a furanyl         group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl         group, a pyridazinyl group, a quinolinyl group, an isoquinolinyl         group, a benzofuranyl group, a benzothiophenyl group,         —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), and —B(Q₃₁)(Q₃₂), and     -   Q₃₁ to Q₃₃ may each independently be selected from a C₁-C₂₀         alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl         group, a terphenyl group, a naphthyl group, and a pyridinyl         group.

For example, L₁ to L₃ may each independently be selected from:

-   -   a benzene group; and     -   a benzene group substituted with at least one selected from         deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a         nitro group, an amidino group, a hydrazino group, a hydrazono         group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀         alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group,         a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a         C₁-C₁ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀         aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl         group, a monovalent non-aromatic condensed polycyclic group, a         monovalent non-aromatic condensed heteropolycyclic group,         —Si(Q₂₁)(Q₂₂)(Q₂₃), —N(Q₂₁)(Q₂₂), —B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁),         —S(═O)₂(Q₂₁), and —P(═O)(Q₂₁)(Q₂₂).

In one embodiment, L₁ to L₃ may each independently be selected from groups represented by Formulae 3-1 to 3-27:

In Formulae 3-1 to 3-27,

-   -   Y₁₁ may be selected from C(Z₃)(Z₄), N(Z₅), Si(Z₆)(Z₇), O, and S,     -   Z₁ to Z₇ may each independently be selected from hydrogen,         deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a         C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group,         a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group,         a cyclohexenyl group, a phenyl group, a biphenyl group, a         terphenyl group, a naphthyl group, a fluorenyl group, a         spiro-bifluorenyl group, a benzofluorenyl group, a         dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl         group, a fluoranthenyl group, a pyrenyl group, a chrysenyl         group, a pyrrolyl group, a thiophenyl group, a furanyl group, a         silolyl group, an imidazolyl group, a pyrazolyl group, a         thiazolyl group, an isothiazolyl group, an oxazolyl group, an         isoxazolyl group, a pyridinyl group, a pyrazinyl group, a         pyrimidinyl group, a pyridazinyl group, a benzofuranyl group, a         benzothiophenyl group, a benzosilolyl group, a dibenzosilolyl         group, and —Si(Q₃₁)(Q₃₂)(Q₃₃), and

Q₃₁ to Q₃₃ may each independently be selected from a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, and a pyridinyl group,

-   -   d2 may be an integer from 0 to 2,     -   d3 may be an integer from 0 to 3,     -   d4 may be an integer from 0 to 4,     -   d6 may be an integer from 0 to 6,     -   d8 may be an integer from 0 to 8, and     -   * and *′ each indicate a binding site to a neighboring atom.

For example, L₁ to L₃ may each independently be a group represented by one of Formulae 3-1 and 3-2.

In Formula 1, a1 to a3 may each independently be an integer from 0 to 3.

In one embodiment, a1 to a3 may each independently be 0 or 1.

In Formula 1, Ar₁ to Ar₃ may each independently be a group represented by one of Formulae 2-1 to 2-7,

-   -   wherein, in Formulae 2-1 to 2-7, Y₁ is O or S, and     -   wherein, in Formulae 1 and 2-1 to 2-7, R₁ to R₁₆ may each         independently be selected from hydrogen, deuterium, —F, —Cl,         —Br, —I, a hydroxyl group, a cyano group, a nitro group, an         amino group, an amidino group, a hydrazine group, a hydrazone         group, a carboxylic acid group or a salt thereof, a sulfonic         acid group or a salt thereof, a phosphoric acid group or a salt         thereof, a substituted or unsubstituted C₁-C₆₀ alkyl group, a         substituted or unsubstituted C₂-C₆₀ alkenyl group, a substituted         or unsubstituted C₂-C₆₀ alkynyl group, a substituted or         unsubstituted C₁-C₆₀ alkoxy group, a substituted or         unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or         unsubstituted C₂-C₁₀ heterocycloalkyl group, a substituted or         unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or         unsubstituted C₂-C₁₀ heterocycloalkenyl group, a substituted or         unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted         C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀         arylthio group, a substituted or unsubstituted C₂-C₆₀ heteroaryl         group, a substituted or unsubstituted monovalent non-aromatic         condensed polycyclic group, a substituted or unsubstituted         monovalent non-aromatic condensed heteropolycyclic group,         —Si(Q₁)(Q₂)(Q₃), —N(Q₁)(Q₂), —B(Q₁)(Q₂), —S(═O)₂(Q₁), and         —P(═O)(Q₁)(Q₂),     -   b3 may be an integer from 0 to 3, b4 may be an integer from 0 to         4, and b5 may be an integer from 0 to 5,     -   wherein, in the groups included in the heterocyclic compound         represented by Formula 1, at least one selected from         substituents R₁ to R₁₁ of Formulae 2-1 to 2-7 may be         —Si(Q₁)(Q₂)(Q₃),     -   when Ar₁ is the group represented by Formula 2-7, a1 may be 0,         when Ar₂ is the group represented by Formula 2-7, a2 may be 0,         and when Ar₃ is a group represented by Formula 2-7, a3 may be 0,     -   when Ar₁ is the group represented by Formula 2-7, Ar₂ and Ar₃         may not be the group represented by Formula 2-1 and L₂ and L₃         may not be a benzene group, when Ar₂ is the group represented by         Formula 2-7, Ar₁ and Ar₃ may not be the group represented by         Formula 2-1 and L₁ and L₃ may not be a benzene group, and when         Ar₃ is the group represented by Formula 2-7, Ar₁ and Ar₂ may not         be the group represented by Formula 2-1 and L₁ and L₂ may not be         a benzene group, and     -   a case in which each of Ar₁ to Ar₃ is the group represented by         Formula 2-1 may be excluded.

In one embodiment, at least one selected from Ar₁ to Ar₃ may be a group different from the others thereof.

In one embodiment, at least one selected from Ar₁ to Ar₃ may be a group represented by one selected from Formulae 2-2 to 2-4.

For example, i) Ar₁ and Ar₂ may each be a group represented by Formula 2-1, and Ar₃ may be a group represented by Formula 2-2;

-   -   ii) Ar₁ and Ar₂ may each be a group represented by Formula 2-1,         and Ar₃ may be a group represented by Formula 2-3;     -   iii) Ar₁ and Ar₂ may each be a group represented by Formula 2-1,         and Ar₃ may be a group represented by Formula 2-4;     -   iv) Ar₁ may be a group represented by Formula 2-1, and Ar₂ and         Ar₃ may each be a group represented by Formula 2-3;     -   v) Ar₁ may be a group represented by Formula 2-1, and Ar₂ and         Ar₃ may each be a group represented by Formula 2-4;     -   vi) Ar₁ and Ar₂ may each be a group represented by Formula 2-3,         and Ar₃ may be a group represented by Formula 2-6;     -   vii) Ar₁ may be a group represented by Formula 2-1, Ar₂ may be a         group represented by Formula 2-2, and Ar₃ may be a group         represented by Formula 2-3; or     -   viii) Ar₁ may be a group represented by Formula 2-1, Ar₂ may be         a group represented by Formula 2-3, and Ar₃ may be a group         represented by Formula 2-6, but embodiments of the present         disclosure are not limited thereto.

In one embodiment, i) when Ar₁ is a group represented by Formula 2-1, at least one selected from R₁(s) in the number of b5 may be —Si(Q₁)(Q₂)(Q₃), and

-   -   ii) when Ar₁ and Ar₂ are each a group represented by Formula 2-3         and Ar₃ is a group represented by Formula 2-6, at least one         selected from R₁₀(s) in the number of b4 and R₁₁(s) in the         number of b3 may be —Si(Q₁)(Q₂)(Q₃).

In one or more embodiments, Ar₁ to Ar₃ may each independently be a group represented by one selected from Formulae 2-1(1) to 2-1(3), 2-2(1) and 2-2(2), 2-3(1) and 2-3(2), 2-4(1) and 2-4(2), and 2-6(1) to 2-6(4):

In Formulae 2-1 (1) to 2-1 (3), 2-2(1) and 2-2(2), 2-3(1) and 2-3(2), 2-4(1) and 2-4(2), and 2-6(1) to 2-6(4),

Z₁₁ to Z₁₅ may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a C₁-C₂₀ alkyl group, a C₁-C₂₀alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a silolyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a benzofuranyl group, a benzothiophenyl group, a benzosilolyl group, a dibenzosilolyl group, and —Si(Q₃₁)(Q₃₂)(Q₃₃),

-   -   Q₃₁ to Q₃₃ may each independently be selected from a C₁-C₂₀         alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl         group, a terphenyl group, a naphthyl group, and a pyridinyl         group,     -   e3 may be an integer from 0 to 3,     -   e4 may be an integer from 0 to 4,     -   e5 may be an integer from 0 to 5,     -   Ph indicates a phenyl group, and     -   * indicates a binding site to a neighboring atom.

For example, at least one selected from Ar₁ to Ar₃ may be a group represented by one selected from Formulae 2-1(2), 2-1(3), 2-2(2), 2-3(2), 2-6(3), and 2-6(4), but embodiments of the present disclosure are not limited thereto.

In one or more embodiments, Ar₁ to Ar₃ may each independently be a group represented by one selected from Formulae 4-1 to 4-21:

In Formulae 4-1 to 4-21,

-   -   Ph indicates a phenyl group, t-Bu indicates a tert-butyl group,         and * indicates a binding site to a neighboring atom.     -   For example, in Formulae 2-1 to 2-7, b3, b4, and b5 may each         independently be 0 or 1.

In one embodiment, in Formulae 1 and 2-1 to 2-7, R to R₁₆ may each independently be selected from hydrogen, a cyano group, a substituted or unsubstituted C₆-C₆₀alkyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, and —Si(Q₁)(Q₂)(Q₃).

For example, R₁ to R₁₆ may each independently be selected from:

hydrogen, a cyano group, a methyl group, an ethyl group, a propyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, an isoamyl group, a hexyl group, and a phenyl group; and

-   -   a methyl group, an ethyl group, a propyl group, an isobutyl         group, a sec-butyl group, a tert-butyl group, a pentyl group, an         isoamyl group, a hexyl group, and a phenyl group, each         substituted with at least one selected from deuterium, —F, —Cl,         —Br, and —I.

In one embodiment, i) X₁ to X₃ may each be N; ii) X₁ and X₂ may each be N, and X₃ may be C(R₁₅); iii) X₁ and X₃ may each be N, and X₂ may be C(R₁₅); iv) X₂ and X₃ may each be N, and X₁ may be C(R₁₅); v) X₁ may be N, and X₂ and X₃ may each be C(R₁₅); vi) X₂ may be N, and X₁ and X₃ may each be C(R₁₅); or vii) X₃ may be N, and X₁ and X₂ may each be C(R₁₅), and R₁₅ may be hydrogen.

At least one substituent of the substituted C₃-C₆₀ carbocyclic group, the substituted C₁-C₆₀ heterocyclic group, the substituted C₁-C₆₀ alkyl group, the substituted C₂-C₆₀ alkenyl group, the substituted C₂-C₆₀ alkynyl group, the substituted C₁-C₆₀ alkoxy group, the substituted C₃-C₁₀ cycloalkyl group, the substituted C₂-C₁₀ heterocycloalkyl group, the substituted C₃-C₁₀ cycloalkenyl group, the substituted C₂-C₁₀ heterocycloalkenyl group, the substituted C₆-C₆₀ aryl group, the substituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀ arylthio group, the substituted C₂-C₆₀ heteroaryl group, the substituted monovalent non-aromatic condensed polycyclic group, and the substituted monovalent non-aromatic condensed heteropolycyclic group may be selected from:

-   -   deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a         nitro group, an amidino group, a hydrazino group, a hydrazono         group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀         alkynyl group, and a C₁-C₆₀ alkoxy group;     -   a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl         group, and a C₁-C₆₀ alkoxy group, each substituted with at least         one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group,         a cyano group, a nitro group, an amidino group, a hydrazino         group, a hydrazono group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀         heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁         heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy         group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a         monovalent non-aromatic condensed polycyclic group, a monovalent         non-aromatic condensed heteropolycyclic group,         —Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁),         —S(═O)₂(Q₁₁), and —P(═O)(Q₁₁)(Q₁₂);     -   a C₃-C₁₀ cycloalkyl group, a C₁-C₁ heterocycloalkyl group, a         C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a         C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio         group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic         condensed polycyclic group, a monovalent non-aromatic condensed         heteropolycyclic group, a biphenyl group, and a terphenyl group;     -   a C₃-C₁₀ cycloalkyl group, a C₁-C₁ heterocycloalkyl group, a         C₃-C₁₀ cycloalkenyl group, a C₁-C₁ heterocycloalkenyl group, a         C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio         group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic         condensed polycyclic group, a monovalent non-aromatic condensed         heteropolycyclic group, a biphenyl group, and a terphenyl group,         each substituted with at least one selected from deuterium, —F,         —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an         amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀         alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a         C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁         heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₁₀         heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy         group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a         monovalent non-aromatic condensed polycyclic group, a monovalent         non-aromatic condensed heteropolycyclic group, a biphenyl group,         a terphenyl group, —Si(Q₂₁)(Q₂₂)(Q₂₃), —N(Q₂₁)(Q₂₂),         —B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), and —P(═O)(Q₂₁)(Q₂₂);         and     -   —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁),         —S(═O)₂(Q₃₁) and —P(═O)(Q₃₁)(Q₃₂), and     -   Q₁ to Q₃, Q₁₁ to Q₁₃, Q₂₁ to Q₂₃, and Q₃₁ to Q₃₃ may each         independently be selected from:     -   hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano         group, a nitro group, an amidino group, a hydrazino group, a         hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a         C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl         group, a C₁-C₁₁ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl         group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a         C₆-C₆₀ aryl group substituted with a C₁-C₆₀ alkyl group, a         C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed         polycyclic group, a monovalent non-aromatic condensed         heteropolycyclic group, a biphenyl group, and a terphenyl group;         and

a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryl group substituted with a C₁-C₆₀ alkyl group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, a biphenyl group, and a terphenyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, and —Si(R_(a))(R_(b))(R_(c)),

-   -   R_(a) to Re may each independently be selected from hydrogen,         deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a         nitro group, an amino group, an amidino group, a hydrazine         group, a hydrazone group, a carboxylic acid group or a salt         thereof, a sulfonic acid group or a salt thereof, a phosphoric         acid group or a salt thereof, a substituted or unsubstituted         C₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀         alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl         group, a substituted or unsubstituted C₁-C₆₀ alkoxy group, a         substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a         substituted or unsubstituted C₂-C₁₀ heterocycloalkyl group, a         substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a         substituted or unsubstituted C₂-C₁₀ heterocycloalkenyl group, a         substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or         unsubstituted C₆-C₆₀ aryloxy group, a substituted or         unsubstituted C₆-C₆₀ arylthio group, a substituted or         unsubstituted C₂-C₆₀ heteroaryl group, a substituted or         unsubstituted monovalent non-aromatic condensed polycyclic         group, and a substituted or unsubstituted monovalent         non-aromatic condensed heteropolycyclic group, wherein the         substituents referred herein are the same as defined above.

In one embodiment, the heterocyclic compound may be selected from Compounds 1 to 59, but embodiments of the present disclosure are not limited thereto:

The heterocyclic compound of embodiments of the present disclosure has an azine-based core including at least one N atom, and the heterocyclic compound further includes substituents having a large size, such as the groups represented by Formulae 2-1 to 2-7. Therefore, because intermolecular attraction is reduced through steric hindrance caused by the substituents having a large size and because the heterocyclic compound has a relatively high triplet energy level, the heterocyclic compound may be suitable as a phosphorescent host.

In the heterocyclic compound according to embodiments of the disclosure, when a silyl group substituted benzene group is included in the substituent of the azine-based core, when the silyl group is substituted at an ortho or meta position with respect to a linked position between the benzene group and the azine-based core, a triplet energy level difference may be increased, as compared with a case in which the silyl group is substituted at a para position, thereby providing excellent phosphorescence.

Therefore, an electronic device such as, for example, an organic light-emitting device, which includes the heterocyclic compound represented by Formula 1, may have a low driving voltage, high efficiency, and a long lifespan.

A synthesis method for the heterocyclic compound represented by Formula 1 should be readily apparent to those of ordinary skill in the art by referring to the following examples.

At least one of the heterocyclic compound of Formula 1 may be used between a pair of electrodes of an organic light-emitting device. For example, the heterocyclic compound may be included in an emission layer. In one or more embodiments, the heterocyclic compound represented by Formula 1 may be used as a material for forming a capping layer positioned outside the pair of electrodes of the organic light-emitting device.

Accordingly, there is provided an organic light-emitting device including: a first electrode; a second electrode facing the first electrode; and an organic layer between the first electrode and the second electrode, the organic layer including an emission layer and at least one heterocyclic compound represented by Formula 1.

The expression “(an organic layer) includes at least one of the heterocyclic compounds,” as used herein, may include a case in which “(an organic layer) includes identical heterocyclic compounds represented by Formula 1” and a case in which “(an organic layer) includes two or more different heterocyclic compounds represented by Formula 1.”

For example, the organic layer may include, as the heterocyclic compound, only Compound 1. In this regard, Compound 1 may be included in an emission layer of the organic light-emitting device. In one or more embodiments, the organic layer may include, as the heterocyclic compound, Compound 1 and Compound 2. In this regard, Compound 1 and Compound 2 may be included in an identical layer (for example, Compound 1 and Compound 2 may both be included in an emission layer), or different layers (for example, Compound 1 may be included in an emission layer and Compound 2 may be included in an electron transport layer).

According to one embodiment,

-   -   the first electrode of the organic light-emitting device may be         an anode,     -   the second electrode of the organic light-emitting device may be         a cathode,     -   the organic layer may include at least one of the heterocyclic         compound represented by Formula 1,     -   the organic layer may further include a hole transport region         between the first electrode and the emission layer and an         electron transport region between the emission layer and the         second electrode,     -   the hole transport region may include a hole injection layer, a         hole transport layer, an emission auxiliary layer, an electron         blocking layer, or any combination thereof, and     -   the electron transport region may include a hole blocking layer,         an electron transport layer, an electron injection layer, or any         combination thereof.

In one or more embodiments, the emission layer may include the heterocyclic compound represented by Formula 1.

In one or more embodiments, the emission layer may include a dopant and a host, and the host may include at least one of the heterocyclic compound represented by Formula 1.

In one embodiment, an amount of the heterocyclic compound may be in a range of about 50 parts by weight to about 99.9 parts by weight based on 100 parts by weight of the emission layer.

For example, the dopant may be a phosphorescent dopant.

In one embodiment, the dopant may include an organometallic complex represented by Formula 401:

In Formulae 401 and 402,

-   -   M may be selected from iridium (Ir), platinum (Pt), palladium         (Pd), osmium (Os), titanium (Ti), zirconium (Zr), hafnium (Hf),         europium (Eu), terbium (Tb), rhodium (Rh), and thulium (Tm),     -   L₄₀₁ may be selected from ligands represented by Formula 402,         and xc1 may be 1, 2, or 3, wherein, when xc1 is two or more, two         or more L₄₀₁ (s) may be identical to or different from each         other,     -   L₄₀₂ may be an organic ligand, and xc2 may be an integer from 0         to 4, wherein, when xc2 is two or more, two or more L₄₀₂(s) may         be identical to or different from each other,     -   X₄₀₁ to X₄₀₄ may each independently be N or C,     -   X₄₀₁ and X₄₀₃ may be linked via a single bond or a double bond,         and X₄₀₂ and X₄₀₄ may be linked via a single bond or a double         bond,     -   A₄₀₁ and A₄₀₂ may each independently be a C₅-C₆₀ carbocyclic         group or a C₁-C₆₀ heterocyclic group,     -   X₄₀₅ may be a single bond, *—O—*′, *—S—*′, *—C(═O)—*′,         *—N(Q₄₁)*, *—C(Q₄₁₁)(Q₄₁₂)-*′, *—C(Q₄₁₁)=C(Q₄₁₂)-*′,         *—C(Q₄₁₁)=*′, or *═C═*′, wherein Q₄₁₁ and Q₄₁₂ may each         independently be hydrogen, deuterium, a C₁-C₂₀ alkyl group, a         C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a         terphenyl group, or a naphthyl group,     -   X₄₀₆ may be a single bond, O, or S,     -   R₄₀₁ and R₄₀₂ may each independently be selected from hydrogen,         deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a         nitro group, an amidino group, a hydrazino group, a hydrazono         group, a substituted or unsubstituted C₁-C₂₀ alkyl group, a         substituted or unsubstituted C₁-C₂₀ alkoxy group, a substituted         or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or         unsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted or         unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or         unsubstituted C₁-C₁ heterocycloalkenyl group, a substituted or         unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted         C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀         arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroaryl         group, a substituted or unsubstituted monovalent non-aromatic         condensed polycyclic group, a substituted or unsubstituted         monovalent non-aromatic condensed heteropolycyclic group,         —Si(Q₄₀₁)(Q₄₀₂)(Q₄₀₃), —N(Q₄₀₁)(Q₄₀₂), —B(Q₄₀₁)(Q₄₀₂),         —C(═O)(Q₄₀₁), —S(═O)₂(Q₄₀₁), and —P(═O)(Q₄₀₁)(Q₄₀₂), wherein         Q₄₀₁ to Q₄₀₃ may each independently be selected from a         C₁-C₁₀alkyl group, a C₁-C₁ alkoxy group, a C₆-C₂₀ aryl group,         and a C₁-C₂₀ heteroaryl group,     -   xc11 and xc12 may each independently be an integer from 0 to 10,         and     -   * and *′ in Formula 402 each indicate a binding site to M in         Formula 401.

In one embodiment, the hole transport region may include a p-dopant having a lowest unoccupied molecular orbital (LUMO) energy level of about −3.5 eV or less.

In one embodiment, the electron transport region may include an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal compound, an alkaline earth metal compound, a rare earth metal compound, an alkali metal complex, alkaline earth metal complex, a rare earth metal complex, or any combination thereof.

In one embodiment, the emission layer may be a first emission layer configured to emit a first color light, and

-   -   the organic light-emitting device may further include i) at         least one second emission layer configured to emit a second         color light or ii) at least one second emission layer configured         to emit a second color light and at least one third emission         layer configured to emit a third color light, between the first         electrode and the second electrode.

A maximum emission wavelength of the first color light, a maximum emission wavelength of the second color light, and a maximum emission wavelength of the third color light may be identical to or different from each other, and

-   -   the first color light and the second color light may be emitted         in the form of mixed light, or the first color light, the second         color light, and the third color light may be emitted in the         form of mixed light.

The term “organic layer,” as used herein, refers to a single layer and/or a plurality of layers between the first electrode and the second electrode of an organic light-emitting device. A material included in the “organic layer” is not limited to an organic material. For example, the organic layer may include an inorganic material.

For example, the organic light-emitting device may have i) a stacked structure including a first electrode, an organic layer, a second electrode, and a second capping layer which are sequentially stacked in this stated order, ii) a stacked structure including a first capping layer, a first electrode, an organic layer, and a second electrode which are sequentially stacked in this stated order, or iii) a stacked structure including a first capping layer, a first electrode, an organic layer, a second electrode, and a second capping layer which are sequentially stacked in this stated order, and at least one selected from the first capping layer and the second capping layer may include the heterocyclic compound.

Description of FIG. 1

FIG. 1 is a schematic view of an organic light-emitting device 10 according to an embodiment. The organic light-emitting device 10 includes a first electrode 110, an organic layer 150, and a second electrode 190.

Hereinafter, the structure of the organic light-emitting device 10 according to an embodiment and a method of manufacturing the organic light-emitting device 10 will be described in connection with FIG. 1 .

First Electrode 110

In FIG. 1 , a substrate may be additionally located under the first electrode 110 or above the second electrode 190. The substrate may be a glass substrate or a plastic substrate, each having excellent mechanical strength, thermal stability, transparency, surface smoothness, ease of handling, and water resistance.

The first electrode 110 may be formed by depositing or sputtering a material for forming the first electrode 110 on the substrate. When the first electrode 110 is an anode, the material for a first electrode 110 may be selected from materials with a high work function to facilitate hole injection.

The first electrode 110 may be a reflective electrode, a semi-transmissive electrode, or a transmissive electrode. When the first electrode 110 is a transmissive electrode, a material for forming a first electrode 110 may be selected from indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO₂), zinc oxide (ZnO), and any combinations thereof, but embodiments of the present disclosure are not limited thereto. In one or more embodiments, when the first electrode 110 is a semi-transmissive electrode or a reflective electrode, a material for forming a first electrode 110 may be selected from magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), magnesium-silver (Mg—Ag), and any combinations thereof, but embodiments of the present disclosure are not limited thereto.

The first electrode 110 may have a single-layered structure, or a multi-layered structure including two or more layers. For example, the first electrode 110 may have a three-layered structure of ITO/Ag/ITO, but the structure of the first electrode 110 is not limited thereto.

Organic Layer 150

The organic layer 150 is located on the first electrode 110. The organic layer 150 may include an emission layer.

The organic layer 150 may further include a hole transport region between the first electrode 110 and the emission layer, and an electron transport region between the emission layer and the second electrode 190.

Hole Transport Region in Organic Layer 150

The hole transport region may have i) a single-layered structure including a single layer including a single material, ii) a single-layered structure including a single layer including a plurality of different materials, or iii) a multi-layered structure having a plurality of layers including a plurality of different materials.

The hole transport region may include at least one layer selected from a hole injection layer, a hole transport layer, an emission auxiliary layer, and an electron blocking layer.

For example, the hole transport region may have a single-layered structure including a single layer including a plurality of different materials, or a multi-layered structure having a hole injection layer/hole transport layer structure, a hole injection layer/hole transport layer/emission auxiliary layer structure, a hole injection layer/emission auxiliary layer structure, a hole transport layer/emission auxiliary layer structure, or a hole injection layer/hole transport layer/electron blocking layer structure, wherein for each structure, constituting layers are sequentially stacked from the first electrode 110 in this stated order, but the structure of the hole transport region is not limited thereto.

The hole transport region may include at least one selected from m-MTDATA, TDATA, 2-TNATA, NPB(NPD), β-NPB, TPD, Spiro-TPD, Spiro-NPB, methylated-NPB, TAPC, HMTPD, 4,4′,4″-tris(N-carbazolyl)triphenylamine (TCTA), polyaniline/dodecylbenzenesulfonic acid (PANI/DBSA), poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS), polyaniline/camphor sulfonic acid (PANI/CSA), polyaniline/poly(4-styrenesulfonate) (PANI/PSS), a compound represented by Formula 201, and a compound represented by Formula 202:

In Formulae 201 and 202,

-   -   L₂₀₁ to L₂₀₄ may each independently be selected from a         substituted or unsubstituted C₃-C₁₀ cycloalkylene group, a         substituted or unsubstituted C₁-C₁₀ heterocycloalkylene group, a         substituted or unsubstituted C₃-C₁₀ cycloalkenylene group, a         substituted or unsubstituted C₁-C₁₀ heterocycloalkenylene group,         a substituted or unsubstituted C₆-C₆₀ arylene group, a         substituted or unsubstituted C₁-C₆₀ heteroarylene group, a         substituted or unsubstituted divalent non-aromatic condensed         polycyclic group, and a substituted or unsubstituted divalent         non-aromatic condensed heteropolycyclic group,     -   L₂₀₅ may be selected from *—O—*′, *—S—*′, *—N(Q₂₀₁)-*′, a         substituted or unsubstituted C₁-C₂₀ alkylene group, a         substituted or unsubstituted C₂-C₂₀ alkenylene group, a         substituted or unsubstituted C₃-C₁₀ cycloalkylene group, a         substituted or unsubstituted C₁-C₁₀ heterocycloalkylene group, a         substituted or unsubstituted C₃-C₁₀ cycloalkenylene group, a         substituted or unsubstituted C₁-C₁₀ heterocycloalkenylene group,         a substituted or unsubstituted C₆-C₆₀ arylene group, a         substituted or unsubstituted C₁-C₆₀ heteroarylene group, a         substituted or unsubstituted divalent non-aromatic condensed         polycyclic group, and a substituted or unsubstituted divalent         non-aromatic condensed heteropolycyclic group,     -   xa1 to xa4 may each independently be an integer from 0 to 3,     -   xa5 may be an integer from 1 to 10, and     -   R₂₀₁ to R₂₀₄ and Q₂₀₁ may each independently be selected from a         substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a         substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a         substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a         substituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, a         substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or         unsubstituted C₆-C₆₀ aryloxy group, a substituted or         unsubstituted C₆-C₆₀ arylthio group, a substituted or         unsubstituted C₁-C₆₀ heteroaryl group, a substituted or         unsubstituted monovalent non-aromatic condensed polycyclic         group, and a substituted or unsubstituted monovalent         non-aromatic condensed heteropolycyclic group.

For example, in Formula 202, R₂₀₁ and R₂₀₂ may optionally be linked via a single bond, a dimethyl-methylene group, or a diphenyl-methylene group, and R₂₀₃ and R₂₀₄ may optionally be linked via a single bond, a dimethyl-methylene group, or a diphenyl-methylene group.

In one or more embodiments, in Formulae 201 and 202,

-   -   L₂₀₁ to L₂₀₅ may each independently be selected from:     -   a phenylene group, a pentalenylene group, an indenylene group, a         naphthylene group, an azulenylene group, a heptalenylene group,         an indacenylene group, an acenaphthylene group, a fluorenylene         group, a spiro-bifluorenylene group, a benzofluorenylene group,         a dibenzofluorenylene group, a phenalenylene group, a         phenanthrenylene group, an anthracenylene group, a         fluoranthenylene group, a triphenylenylene group, a pyrenylene         group, a chrysenylene group, a naphthacenylene group, a         picenylene group, a perylenylene group, a pentaphenylene group,         a hexacenylene group, a pentacenylene group, a rubicenylene         group, a coronenylene group, an ovalenylene group, a         thiophenylene group, a furanylene group, a carbazolylene group,         an indolylene group, an isoindolylene group, a benzofuranylene         group, a benzothiophenylene group, a dibenzofuranylene group, a         dibenzothiophenylene group, a benzocarbazolylene group, a         dibenzocarbazolylene group, a dibenzosilolylene group, and a         pyridinylene group; and     -   a phenylene group, a pentalenylene group, an indenylene group, a         naphthylene group, an azulenylene group, a heptalenylene group,         an indacenylene group, an acenaphthylene group, a fluorenylene         group, a spiro-bifluorenylene group, a benzofluorenylene group,         a dibenzofluorenylene group, a phenalenylene group, a         phenanthrenylene group, an anthracenylene group, a         fluoranthenylene group, a triphenylenylene group, a pyrenylene         group, a chrysenylene group, a naphthacenylene group, a         picenylene group, a perylenylene group, a pentaphenylene group,         a hexacenylene group, a pentacenylene group, a rubicenylene         group, a coronenylene group, an ovalenylene group, a         thiophenylene group, a furanylene group, a carbazolylene group,         an indolylene group, an isoindolylene group, a benzofuranylene         group, a benzothiophenylene group, a dibenzofuranylene group, a         dibenzothiophenylene group, a benzocarbazolylene group, a         dibenzocarbazolylene group, a dibenzosilolylene group, and a         pyridinylene group, each substituted with at least one selected         from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano         group, a nitro group, an amidino group, a hydrazino group, a         hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a         cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a         cyclopentenyl group, a cyclohexenyl group, a phenyl group, a         biphenyl group, a terphenyl group, a phenyl group substituted         with a C₁-C₁₀ alkyl group, a phenyl group substituted with —F, a         pentalenyl group, an indenyl group, a naphthyl group, an         azulenyl group, a heptalenyl group, an indacenyl group, an         acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group,         a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl         group, a phenanthrenyl group, an anthracenyl group, a         fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a         chrysenyl group, a naphthacenyl group, a picenyl group, a         perylenyl group, a pentaphenyl group, a hexacenyl group, a         pentacenyl group, a rubicenyl group, a coronenyl group, an         ovalenyl group, a thiophenyl group, a furanyl group, a         carbazolyl group, an indolyl group, an isoindolyl group, a         benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl         group, a dibenzothiophenyl group, a benzocarbazolyl group, a         dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl         group, —Si(Q₃₁)(Q₃₂)(Q₃₃), and —N(Q₃₁)(Q₃₂), and     -   Q₃₁ to Q₃₃ may each independently be selected from a C₁-C₁₀         alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl         group, a terphenyl group, and a naphthyl group.

In one or more embodiments, xa1 to xa4 may each independently be 0, 1, or 2.

In one or more embodiments, xa5 may be 1, 2, 3, or 4.

In one or more embodiments, R₂₀₁ to R₂₀₄ and Q₂₀₁ may each independently be selected from:

-   -   a phenyl group, a biphenyl group, a terphenyl group, a         pentalenyl group, an indenyl group, a naphthyl group, an         azulenyl group, a heptalenyl group, an indacenyl group, an         acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group,         a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl         group, a phenanthrenyl group, an anthracenyl group, a         fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a         chrysenyl group, a naphthacenyl group, a picenyl group, a         perylenyl group, a pentaphenyl group, a hexacenyl group, a         pentacenyl group, a rubicenyl group, a coronenyl group, an         ovalenyl group, a thiophenyl group, a furanyl group, a         carbazolyl group, an indolyl group, an isoindolyl group, a         benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl         group, a dibenzothiophenyl group, a benzocarbazolyl group, a         dibenzocarbazolyl group, a dibenzosilolyl group, and a pyridinyl         group; and     -   a phenyl group, a biphenyl group, a terphenyl group, a         pentalenyl group, an indenyl group, a naphthyl group, an         azulenyl group, a heptalenyl group, an indacenyl group, an         acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group,         a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl         group, a phenanthrenyl group, an anthracenyl group, a         fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a         chrysenyl group, a naphthacenyl group, a picenyl group, a         perylenyl group, a pentaphenyl group, a hexacenyl group, a         pentacenyl group, a rubicenyl group, a coronenyl group, an         ovalenyl group, a thiophenyl group, a furanyl group, a         carbazolyl group, an indolyl group, an isoindolyl group, a         benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl         group, a dibenzothiophenyl group, a benzocarbazolyl group, a         dibenzocarbazolyl group, a dibenzosilolyl group, and a pyridinyl         group, each substituted with at least one selected from         deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a         nitro group, an amidino group, a hydrazino group, a hydrazono         group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a         cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a         cyclopentenyl group, a cyclohexenyl group, a phenyl group, a         biphenyl group, a terphenyl group, a phenyl group substituted         with a C₁-C₁₀ alkyl group, a phenyl group substituted with —F, a         pentalenyl group, an indenyl group, a naphthyl group, an         azulenyl group, a heptalenyl group, an indacenyl group, an         acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group,         a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl         group, a phenanthrenyl group, an anthracenyl group, a         fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a         chrysenyl group, a naphthacenyl group, a picenyl group, a         perylenyl group, a pentaphenyl group, a hexacenyl group, a         pentacenyl group, a rubicenyl group, a coronenyl group, an         ovalenyl group, a thiophenyl group, a furanyl group, a         carbazolyl group, an indolyl group, an isoindolyl group, a         benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl         group, a dibenzothiophenyl group, a benzocarbazolyl group, a         dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl         group, —Si(Q₃₁)(Q₃₂)(Q₃₃), and —N(Q₃₁)(Q₃₂), and     -   Q₃₁ to Q₃₃ are the same as described above.

In one or more embodiments, in Formula 201, at least one selected from R₂₀₁ to R₂₀₃ may each independently be selected from:

a fluorenyl group, a spiro-bifluorenyl group, a carbazolyl group, a dibenzofuranyl group, and a dibenzothiophenyl group; and

a fluorenyl group, a spiro-bifluorenyl group, a carbazolyl group, a dibenzofuranyl group, and a dibenzothiophenyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a phenyl group substituted with a C₁-C₁₀ alkyl group, a phenyl group substituted with —F, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a carbazolyl group, a dibenzofuranyl group, and a dibenzothiophenyl group,

-   -   but embodiments of the present disclosure are not limited         thereto.

In one or more embodiments, in Formula 202, i) R₂₀₁ and R₂₀₂ may be linked via a single bond, and/or ii) R₂₀₃ and R₂₀₄ may be linked via a single bond.

In one or more embodiments, in Formula 202, at least one selected from R₂₀₁ to R₂₀₄ may be selected from:

-   -   a carbazolyl group; and     -   a carbazolyl group substituted with at least one selected from         deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a         nitro group, an amidino group, a hydrazino group, a hydrazono         group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a         cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a         cyclopentenyl group, a cyclohexenyl group, a phenyl group, a         biphenyl group, a terphenyl group, a phenyl group substituted         with a C₁-C₁₀ alkyl group, a phenyl group substituted with —F, a         naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a         carbazolyl group, a dibenzofuranyl group, and a         dibenzothiophenyl group,     -   but embodiments of the present disclosure are not limited         thereto.

The compound represented by Formula 201 may be represented by Formula 201A:

In one embodiment, the compound represented by Formula 201 may be represented by Formula 201A(1) below, but embodiments of the present disclosure are not limited thereto:

In one embodiment, the compound represented by Formula 201 may be represented by Formula 201A-1 below, but embodiments of the present disclosure are not limited thereto:

In one embodiment, the compound represented by Formula 202 may be represented by Formula 202A:

In one embodiment, the compound represented by Formula 202 may be represented by Formula 202A-1:

In Formulae 201A, 201A(1), 201A-1, 202A, and 202A-1,

-   -   L₂₀₁ to L₂₀₃, xa1 to xa3, xa5, and R₂₀₂ to R₂₀₄ are the same as         described above,     -   R₂₁₁ and R₂₁₂ may each independently be defined the same as         R₂₀₃.     -   R₂₁₃ to R₂₁₇ may each independently be selected from hydrogen,         deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a         nitro group, an amidino group, a hydrazino group, a hydrazono         group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a         cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a         cyclopentenyl group, a cyclohexenyl group, a phenyl group, a         biphenyl group, a terphenyl group, a phenyl group substituted         with a C₁-C₁₀ alkyl group, a phenyl group substituted with —F, a         pentalenyl group, an indenyl group, a naphthyl group, an         azulenyl group, a heptalenyl group, an indacenyl group, an         acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group,         a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl         group, a phenanthrenyl group, an anthracenyl group, a         fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a         chrysenyl group, a naphthacenyl group, a picenyl group, a         perylenyl group, a pentaphenyl group, a hexacenyl group, a         pentacenyl group, a rubicenyl group, a coronenyl group, an         ovalenyl group, a thiophenyl group, a furanyl group, a         carbazolyl group, an indolyl group, an isoindolyl group, a         benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl         group, a dibenzothiophenyl group, a benzocarbazolyl group, a         dibenzocarbazolyl group, a dibenzosilolyl group, and a pyridinyl         group.

The hole transport region may include at least one compound selected from Compounds HT1 to HT39, but embodiments of the present disclosure are not limited thereto:

A thickness of the hole transport region may be in a range of about 100 Å to about 10,000 Å, and for example, about 100 Å to about 1,000 Å. When the hole transport region includes at least one selected from a hole injection layer and a hole transport layer, the thickness of the hole injection layer may be in a range of about 100 Å to about 9,000 Å, and for example, about 100 Å to about 1,000 Å, and the thickness of the hole transport layer may be in a range of about 50 Å to about 2,000 Å, and for example, about 100 Å to about 1500 Å. When the thicknesses of the hole transport region, the hole injection layer, and the hole transport layer are within these ranges, suitable or satisfactory hole transporting characteristics may be obtained without a substantial increase in driving voltage.

The emission auxiliary layer may increase light-emission efficiency by compensating for an optical resonance distance according to the wavelength of light emitted by an emission layer, and the electron blocking layer may block the flow of electrons from an electron transport region. The emission auxiliary layer and the electron blocking layer may include the materials as described above.

p-Dopant

The hole transport region may further include, in addition to these materials, a charge-generation material for the improvement of conductive properties. The charge-generation material may be homogeneously or non-homogeneously dispersed in the hole transport region.

The charge-generation material may be, for example, a p-dopant.

In one embodiment, the p-dopant may have a LUMO energy level of about −3.5 eV or less.

The p-dopant may include at least one selected from a quinone derivative, a metal oxide, and a cyano group-containing compound, but embodiments of the present disclosure are not limited thereto.

For example, the p-dopant may include at least one selected from:

-   -   a quinone derivative, such as tetracyanoquinodimethane (TCNQ) or         2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ);     -   a metal oxide, such as tungsten oxide or molybdenum oxide;     -   1,4,5,8,9,12-hexaazatriphenylene-hexacarbonitrile (HAT-CN); and     -   a compound represented by Formula 221,     -   but embodiments of the present disclosure are not limited         thereto:

In Formula 221,

-   -   R₂₂₁ to R₂₂₃ may each independently be selected from a         substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a         substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a         substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a         substituted or unsubstituted C₁-C₁ heterocycloalkenyl group, a         substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or         unsubstituted C₁-C₆₀ heteroaryl group, a substituted or         unsubstituted monovalent non-aromatic condensed polycyclic         group, and a substituted or unsubstituted monovalent         non-aromatic condensed heteropolycyclic group, provided that at         least one selected from R₂₂₁ to R₂₂₃ has at least one         substituent selected from a cyano group, —F, —Cl, —Br, —I, a         C₁-C₂₀ alkyl group substituted with —F, a C₁-C₂₀ alkyl group         substituted with —Cl, a C₁-C₂₀ alkyl group substituted with —Br,         and a C₁-C₂₀ alkyl group substituted with —I.

Emission Layer in Organic Layer 150

When the organic light-emitting device 10 is a full-color organic light-emitting device, the emission layer may be patterned into a red emission layer, a green emission layer, or a blue emission layer, according to a sub-pixel. In one or more embodiments, the emission layer may have a stacked structure of two or more layers selected from a red emission layer, a green emission layer, and a blue emission layer, in which the two or more layers contact each other or are separated from each other. In one or more embodiments, the emission layer may include two or more materials selected from a red light-emitting material, a green light-emitting material, and a blue light-emitting material, in which the two or more materials are mixed with each other in a single layer to emit white light.

The emission layer may include the heterocyclic compound represented by Formula 1.

The emission layer may include a host and a dopant. The dopant may include at least one selected from a phosphorescent dopant and a fluorescent dopant.

An amount of the dopant in the emission layer may be in a range of about 0.01 parts by weight to about 15 parts by weight based on 100 parts by weight of the host, but embodiments of the present disclosure are not limited thereto.

A thickness of the emission layer may be in a range of about 100 Å to about 1,000 Å, for example, about 200 Å to about 600 Å. When the thickness of the emission layer is within this range, excellent light-emission characteristics may be obtained without a substantial increase in driving voltage.

Host in Emission Layer

The host may include the heterocyclic compound represented by Formula 1.

In one or more embodiments, the host may further include a compound represented by Formula 301 below.

[Ar₃₀₁]_(xb11)-[(L₃₀₁)_(xb1)-R₃₀₁]_(xb21)  Formula 301

In Formula 301, Ar₃₀₁ may be a substituted or unsubstituted C₅-C₆₀ carbocyclic group or a substituted or unsubstituted C₁-C₆₀ heterocyclic group,

-   -   xb11 may be 1, 2, or 3,     -   L₃₀₁ may be selected from a substituted or unsubstituted C₃-C₁₀         cycloalkylene group, a substituted or unsubstituted C₁-C₁         heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀         cycloalkenylene group, a substituted or unsubstituted C₁-C₁         heterocycloalkenylene group, a substituted or unsubstituted         C₆-C₆₀ arylene group, a substituted or unsubstituted C₁-C₆₀         heteroarylene group, a substituted or unsubstituted divalent         non-aromatic condensed polycyclic group, and a substituted or         unsubstituted divalent non-aromatic condensed heteropolycyclic         group;     -   xb1 may be an integer from 0 to 5,     -   R₃₀₁ may be selected from deuterium, —F, —Cl, —Br, —I, a         hydroxyl group, a cyano group, a nitro group, an amidino group,         a hydrazino group, a hydrazono group, a substituted or         unsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted         C₂-C₆₀ alkenyl group, a substituted or unsubstituted C₂-C₆₀         alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxy         group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a         substituted or unsubstituted C₁-C₁ heterocycloalkyl group, a         substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a         substituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, a         substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or         unsubstituted C₆-C₆₀ aryloxy group, a substituted or         unsubstituted C₆-C₆₀ arylthio group, a substituted or         unsubstituted C₁-C₆₀ heteroaryl group, a substituted or         unsubstituted monovalent non-aromatic condensed polycyclic         group, a substituted or unsubstituted monovalent non-aromatic         condensed heteropolycyclic group, —Si(Q₃₀₁)(Q₃₀₂)(Q₃₀₃),         —N(Q₃₀₁)(Q₃₀₂), —B(Q₃₀₁)(Q₃₀₂), —C(═O)(Q₃₀₁), —S(═O)₂(Q₃₀₁), and         —P(═O)(Q₃₀₁)(Q₃₀₂),     -   xb21 may be an integer from 1 to 5, and     -   Q₃₀₁ to Q₃₀₃ may each independently be selected from a C₁-C₁₀         alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl         group, a terphenyl group, and a naphthyl group, but embodiments         of the present disclosure are not limited thereto.

In one embodiment, Ar₃₀₁ in Formula 301 may be selected from:

-   -   a naphthalene group, a fluorene group, a spiro-bifluorene group,         a benzofluorene group, a dibenzofluorene group, a phenalene         group, a phenanthrene group, an anthracene group, a fluoranthene         group, a triphenylene group, a pyrene group, a chrysene group, a         naphthacene group, a picene group, a perylene group, a         pentaphene group, an indenoanthracene group, a dibenzofuran         group, and a dibenzothiophene group; and     -   a naphthalene group, a fluorene group, a spiro-bifluorene group,         a benzofluorene group, a dibenzofluorene group, a phenalene         group, a phenanthrene group, an anthracene group, a fluoranthene         group, a triphenylene group, a pyrene group, a chrysene group, a         naphthacene group, a picene group, a perylene group, a         pentaphene group, an indenoanthracene group, a dibenzofuran         group, and a dibenzothiophene group, each substituted with at         least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl         group, a cyano group, a nitro group, an amidino group, a         hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a         C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a         terphenyl group, a naphthyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃),         —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and         —P(═O)(Q₃₁)(Q₃₂), and     -   Q₃₁ to Q₃₃ may each independently be selected from a C₁-C₁₀         alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl         group, a terphenyl group, and a naphthyl group, but embodiments         of the present disclosure are not limited thereto.

In Formula 301, when xb11 is two or more, two or more Ar₃₀₁(s) may be linked via a single bond.

In one or more embodiments, the compound represented by Formula 301 may be represented by Formula 301-1 or 301-2:

In Formulae 301-1 and 301-2, A₃₀₁ to A₃₀₄ may each independently be selected from a benzene, a naphthalene, a phenanthrene, a fluoranthene, a triphenylene, a pyrene, a chrysene, a pyridine, a pyrimidine, an indene, a fluorene, a spiro-bifluorene, a benzofluorene, a dibenzofluorene, an indole, a carbazole, benzocarbazole, dibenzocarbazole, a furan, a benzofuran, a dibenzofuran, a naphthofuran, a benzonaphthofuran, dinaphthofuran, a thiophene, a benzothiophene, a dibenzothiophene, a naphthothiophene, a benzonaphthothiophene, and a dinaphthothiophene,

-   -   X₃₀₁ may be O, S, or N-[(L₃₀₄)_(xb4)-R_(304]),     -   R₃₁₁ to R₃₁₄ may each independently be selected from hydrogen,         deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a         nitro group, an amidino group, a hydrazino group, a hydrazono         group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl         group, a biphenyl group, a terphenyl group, a naphthyl group         —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁),         —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),     -   xb22 and xb23 may each independently be 0, 1, or 2,     -   L₃₀₁, xb1, R₃₀₁, and Q₃₁ to Q₃₃ are the same as described above,     -   L₃₀₂ to L₃₀₄ may each independently be defined the same as L₃₀₁,     -   xb2 to xb4 may each independently be defined the same as xb1,         and     -   R₃₀₂ to R₃₀₄ may each independently be defined the same as R₃₀.

For example, in Formulae 301, 301-1, and 301-2, L₃₀₁ to L₃₀₄ may each independently be selected from:

-   -   a phenylene group, a naphthylene group, a fluorenylene group, a         spiro-bifluorenylene group, a benzofluorenylene group, a         dibenzofluorenylene group, a phenanthrenylene group, an         anthracenylene group, a fluoranthenylene group, a         triphenylenylene group, a pyrenylene group, a chrysenylene         group, a perylenylene group, a pentaphenylene group, a         hexacenylene group, a pentacenylene group, a thiophenylene         group, a furanylene group, a carbazolylene group, an indolylene         group, an isoindolylene group, a benzofuranylene group, a         benzothiophenylene group, a dibenzofuranylene group, a         dibenzothiophenylene group, a benzocarbazolylene group, a         dibenzocarbazolylene group, a dibenzosilolylene group, a         pyridinylene group, an imidazolylene group, a pyrazolylene         group, a thiazolylene group, an isothiazolylene group, an         oxazolylene group, an isoxazolylene group, a thiadiazolylene         group, an oxadiazolylene group, a pyrazinylene group, a         pyrimidinylene group, a pyridazinylene group, a triazinylene         group, a quinolinylene group, an isoquinolinylene group, a         benzoquinolinylene group, a phthalazinylene group, a         naphthyridinylene group, a quinoxalinylene group, a         quinazolinylene group, a cinnolinylene group, a         phenanthridinylene group, an acridinylene group, a         phenanthrolinylene group, a phenazinylene group, a         benzimidazolylene group, an isobenzothiazolylene group, a         benzoxazolylene group, an isobenzoxazolylene group, a         triazolylene group, a tetrazolylene group, an         imidazopyridinylene group, an imidazopyrimidinylene group, and         an azacarbazolylene group; and     -   a phenylene group, a naphthylene group, a fluorenylene group, a         spiro-bifluorenylene group, a benzofluorenylene group, a         dibenzofluorenylene group, a phenanthrenylene group, an         anthracenylene group, a fluoranthenylene group, a         triphenylenylene group, a pyrenylene group, a chrysenylene         group, a perylenylene group, a pentaphenylene group, a         hexacenylene group, a pentacenylene group, a thiophenylene         group, a furanylene group, a carbazolylene group, an indolylene         group, an isoindolylene group, a benzofuranylene group, a         benzothiophenylene group, a dibenzofuranylene group, a         dibenzothiophenylene group, a benzocarbazolylene group, a         dibenzocarbazolylene group, a dibenzosilolylene group, a         pyridinylene group, an imidazolylene group, a pyrazolylene         group, a thiazolylene group, an isothiazolylene group, an         oxazolylene group, an isoxazolylene group, a thiadiazolylene         group, an oxadiazolylene group, a pyrazinylene group, a         pyrimidinylene group, a pyridazinylene group, a triazinylene         group, a quinolinylene group, an isoquinolinylene group, a         benzoquinolinylene group, a phthalazinylene group, a         naphthyridinylene group, a quinoxalinylene group, a         quinazolinylene group, a cinnolinylene group, a         phenanthridinylene group, an acridinylene group, a         phenanthrolinylene group, a phenazinylene group, a         benzimidazolylene group, an isobenzothiazolylene group, a         benzoxazolylene group, an isobenzoxazolylene group, a         triazolylene group, a tetrazolylene group, an         imidazopyridinylene group, an imidazopyrimidinylene group, and         an azacarbazolylene group, each substituted with at least one         selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a         cyano group, a nitro group, an amidino group, a hydrazino group,         a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group,         a phenyl group, a biphenyl group, a terphenyl group, a naphthyl         group, a fluorenyl group, a spiro-bifluorenyl group, a         benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl         group, an anthracenyl group, a fluoranthenyl group, a         triphenylenyl group, a pyrenyl group, a chrysenyl group, a         perylenyl group, a pentaphenyl group, a hexacenyl group, a         pentacenyl group, a thiophenyl group, a furanyl group, a         carbazolyl group, an indolyl group, an isoindolyl group, a         benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl         group, a dibenzothiophenyl group, a benzocarbazolyl group, a         dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl         group, an imidazolyl group, a pyrazolyl group, a thiazolyl         group, an isothiazolyl group, an oxazolyl group, an isoxazolyl         group, a thiadiazolyl group, an oxadiazolyl group, a pyrazinyl         group, a pyrimidinyl group, a pyridazinyl group, a triazinyl         group, a quinolinyl group, an isoquinolinyl group, a         benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl         group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl         group, a phenanthridinyl group, an acridinyl group, a         phenanthrolinyl group, a phenazinyl group, a benzimidazolyl         group, an isobenzothiazolyl group, a benzoxazolyl group, an         isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an         imidazopyridinyl group, an imidazopyrimidinyl group, an         azacarbazolyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂),         —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),         and     -   Q₃₁ to Q₃₃ may each independently be the same as described         above.

In one embodiment, in Formulae 301, 301-1, and 301-2, R₃₀₁ to R₃₀₄ may each independently be selected from:

-   -   a phenyl group, a biphenyl group, a terphenyl group, a naphthyl         group, a fluorenyl group, a spiro-bifluorenyl group, a         benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl         group, an anthracenyl group, a fluoranthenyl group, a         triphenylenyl group, a pyrenyl group, a chrysenyl group, a         perylenyl group, a pentaphenyl group, a hexacenyl group, a         pentacenyl group, a thiophenyl group, a furanyl group, a         carbazolyl group, an indolyl group, an isoindolyl group, a         benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl         group, a dibenzothiophenyl group, a benzocarbazolyl group, a         dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl         group, an imidazolyl group, a pyrazolyl group, a thiazolyl         group, an isothiazolyl group, an oxazolyl group, an isoxazolyl         group, a thiadiazolyl group, an oxadiazolyl group, a pyrazinyl         group, a pyrimidinyl group, a pyridazinyl group, a triazinyl         group, a quinolinyl group, an isoquinolinyl group, a         benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl         group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl         group, a phenanthridinyl group, an acridinyl group, a         phenanthrolinyl group, a phenazinyl group, a benzimidazolyl         group, an isobenzothiazolyl group, a benzoxazolyl group, an         isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an         imidazopyridinyl group, an imidazopyrimidinyl group, and an         azacarbazolyl group; and

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, and an azacarbazolyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, an azacarbazolyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), and

-   -   Q₃₁ to Q₃₃ may each independently be the same as described         above.

In one or more embodiments, the host may include an alkaline earth metal complex. For example, the host may be selected from a Be complex (for example, Compound H55), a Mg complex, and a Zn complex.

The host may include at least one selected from 9,10-di(2-naphthyl)anthracene) (ADN), 2-methyl-9,10-bis(naphthalen-2-yl)anthracene (MADN), 9,10-di-(2-naphthyl)-2-t-butyl-anthracene (TBADN), 4,4′-bis(N-carbazolyl)-1,1′-biphenyl (CBP), 1,3-di-9-carbazolylbenzene (mCP), 1,3,5-tri(carbazol-9-yl)benzene (TCP), and Compounds H1 to H55, but embodiments of the present disclosure are not limited thereto:

Phosphorescent Dopant Included in Emission Layer in Organic Layer 150

The phosphorescent dopant may include the organometallic complex represented by Formula 401.

In one embodiment, in Formula 402, A₄₀₁ and A₄₀₂ may each independently be selected from a benzene group, a naphthalene group, a fluorene group, a spiro-bifluorene group, an indene group, a pyrrole group, a thiophene group, a furan group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyrimidine group, a pyridazine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a quinoxaline group, a quinazoline group, a carbazole group, a benzimidazole group, a benzofuran group, a benzothiophene group, an isobenzothiophene group, a benzoxazole group, an isobenzoxazole group, a triazole group, a tetrazole group, an oxadiazole group, a triazine group, a dibenzofuran group, and a dibenzothiophene group.

In one or more embodiments, in Formula 402, i) X₄₀₁ may be nitrogen, and X₄₀₂ may be carbon, or ii) X₄₀₁ and X₄₀₂ may each be nitrogen concurrently (e.g., at the same time).

In one or more embodiments, R₄₀₁ and R₄₀₂ in Formula 402 may each independently be selected from:

-   -   hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano         group, a nitro group, an amidino group, a hydrazino group, a         hydrazono group, a C₁-C₂₀ alkyl group, and a C₁-C₂₀ alkoxy         group;     -   a C₁-C₂₀ alkyl group, and a C₁-C₂₀ alkoxy group, each         substituted with at least one selected from deuterium, —F, —Cl,         —Br, —I, a hydroxyl group, a cyano group, a nitro group, an         amidino group, a hydrazino group, a hydrazono group, a phenyl         group, a naphthyl group, a cyclopentyl group, a cyclohexyl         group, an adamantanyl group, a norbornanyl group, and a         norbornenyl group;     -   a cyclopentyl group, a cyclohexyl group, an adamantanyl group, a         norbornanyl group, a norbornenyl group, a phenyl group, a         biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl         group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl         group, a pyridazinyl group, a triazinyl group, a quinolinyl         group, an isoquinolinyl group, a quinoxalinyl group, a         quinazolinyl group, a carbazolyl group, a dibenzofuranyl group,         and a dibenzothiophenyl group;     -   a cyclopentyl group, a cyclohexyl group, an adamantanyl group, a         norbornanyl group, a norbornenyl group a phenyl group, a         biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl         group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl         group, a pyridazinyl group, a triazinyl group, a quinolinyl         group, an isoquinolinyl group, a quinoxalinyl group, a         quinazolinyl group, a carbazolyl group, a dibenzofuranyl group,         and a dibenzothiophenyl group, each substituted with at least         one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group,         a cyano group, a nitro group, an amidino group, a hydrazino         group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy         group, a cyclopentyl group, a cyclohexyl group, an adamantanyl         group, a norbornanyl group, a norbornenyl group, a phenyl group,         a biphenyl group, a terphenyl group, a naphthyl group, a         fluorenyl group, a pyridinyl group, a pyrazinyl group, a         pyrimidinyl group, a pyridazinyl group, a triazinyl group, a         quinolinyl group, an isoquinolinyl group, a quinoxalinyl group,         a quinazolinyl group, a carbazolyl group, a dibenzofuranyl         group, and a dibenzothiophenyl group; and     -   —Si(Q₄₀₁)(Q₄₀₂)(Q₄₀₃), —N(Q₄₀₁)(Q₄₀₂), —B(Q₄₀₁)(Q₄₀₂),         —C(═O)(Q₄₀₁), —S(═O)₂(Q₄₀₁), and —P(═O)(Q₄₀₁)(Q₄₀₂), and     -   Q₄₀₁ to Q₄₀₃ may each independently be selected from a C₁-C₁₀         alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl         group, and a naphthyl group, but are not limited thereto.

In one or more embodiments, when xc1 in Formula 401 is two or more, two A₄₀₁ (s) in two or more L₄₀₁ (s) may optionally be linked via X₄₀₇, which is a linking group, or two A₄₀₂(s) in two or more L₄₀₁ (s) may optionally be linked via X₄₀₈, which is a linking group (see Compounds PD1 to PD4 and PD7). X₄₀₇ and X₄₀₈ may each independently be a single bond, *—O—*′, *—S—*′, *—C(═O)—*′, *—N(Q₄₁₃)-*′, *—C(Q₄₁₃)(Q₄₁₄)-*′, or *—C(Ω₄₁₃)═C(Q₄₁₄)-*′ (wherein Q₄₁₃ and Q₄₁₄ may each independently be hydrogen, deuterium, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, or a naphthyl group), but embodiments of the present disclosure are not limited thereto.

L₄₀₂ in Formula 401 may be a monovalent, divalent, or trivalent organic ligand. For example, L₄₀₂ may be halogen, diketone (for example, acetylacetonate), carboxylic acid (for example, picolinate), —C(═O), isonitrile, —CN, and a phosphorus-containing material (for example, phosphine or phosphite), but embodiments of the present disclosure are not limited thereto.

In one or more embodiments, the phosphorescent dopant may be selected from, for example, Compounds PD1 to PD26, but embodiments of the present disclosure are not limited thereto:

Fluorescent Dopant in Emission Layer

The fluorescent dopant may include an arylamine compound or a styrylamine compound.

The fluorescent dopant may include a compound represented by Formula 501:

In Formula 501,

-   -   Ar₅₀₁ may be a substituted or unsubstituted C₅-C₆₀ carbocyclic         group or a substituted or unsubstituted C₁-C₆₀ heterocyclic         group,     -   L₅₀₁ to L₅₀₃ may each independently be selected from a         substituted or unsubstituted C₃-C₁₀ cycloalkylene group, a         substituted or unsubstituted C₁-C₁₀ heterocycloalkylene group, a         substituted or unsubstituted C₃-C₁₀ cycloalkenylene group, a         substituted or unsubstituted C₁-C₁ heterocycloalkenylene group,         a substituted or unsubstituted C₆-C₆₀ arylene group, a         substituted or unsubstituted C₁-C₆₀ heteroarylene group, a         substituted or unsubstituted divalent non-aromatic condensed         polycyclic group, and a substituted or unsubstituted divalent         non-aromatic condensed heteropolycyclic group,     -   xd1 to xd3 may each independently be an integer from 0 to 3;     -   R₅₀₁ and R₅₀₂ may each independently be selected from a         substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a         substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a         substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a         substituted or unsubstituted C₁-C₁ heterocycloalkenyl group, a         substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or         unsubstituted C₆-C₆₀ aryloxy group, a substituted or         unsubstituted C₆-C₆₀ arylthio group, a substituted or         unsubstituted C₁-C₆₀ heteroaryl group, a substituted or         unsubstituted monovalent non-aromatic condensed polycyclic         group, and a substituted or unsubstituted monovalent         non-aromatic condensed heteropolycyclic group,     -   xd4 may be an integer from 1 to 6.     -   In one embodiment, Ar₅₀₁ in Formula 501 may be selected from:     -   a naphthalene group, a heptalene group, a fluorene group, a         spiro-bifluorene group, a benzofluorene group, a dibenzofluorene         group, a phenalene group, a phenanthrene group, an anthracene         group, a fluoranthene group, a triphenylene group, a pyrene         group, a chrysene group, a naphthacene group, a picene group, a         perylene group, a pentaphene group, an indenoanthracene group,         and an indenophenanthrene group; and     -   a naphthalene group, a heptalene group, a fluorene group, a         spiro-bifluorene group, a benzofluorene group, a dibenzofluorene         group, a phenalene group, a phenanthrene group, an anthracene         group, a fluoranthene group, a triphenylene group, a pyrene         group, a chrysene group, a naphthacene group, a picene group, a         perylene group, a pentaphene group, an indenoanthracene group,         and an indenophenanthrene group, each substituted with at least         one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group,         a cyano group, a nitro group, an amidino group, a hydrazino         group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy         group, a phenyl group, a biphenyl group, a terphenyl group, and         a naphthyl group.

In one or more embodiments, L₅₀₁ to L₅₀₃ in Formula 501 may each independently be selected from:

-   -   a phenylene group, a naphthylene group, a fluorenylene group, a         spiro-bifluorenylene group, a benzofluorenylene group, a         dibenzofluorenylene group, a phenanthrenylene group, an         anthracenylene group, a fluoranthenylene group, a         triphenylenylene group, a pyrenylene group, a chrysenylene         group, a perylenylene group, a pentaphenylene group, a         hexacenylene group, a pentacenylene group, a thiophenylene         group, a furanylene group, a carbazolylene group, an indolylene         group, an isoindolylene group, a benzofuranylene group, a         benzothiophenylene group, a dibenzofuranylene group, a         dibenzothiophenylene group, a benzocarbazolylene group, a         dibenzocarbazolylene group, a dibenzosilolylene group, and a         pyridinylene group; and     -   a phenylene group, a naphthylene group, a fluorenylene group, a         spiro-bifluorenylene group, a benzofluorenylene group, a         dibenzofluorenylene group, a phenanthrenylene group, an         anthracenylene group, a fluoranthenylene group, a         triphenylenylene group, a pyrenylene group, a chrysenylene         group, a perylenylene group, a pentaphenylene group, a         hexacenylene group, a pentacenylene group, a thiophenylene         group, a furanylene group, a carbazolylene group, an indolylene         group, an isoindolylene group, a benzofuranylene group, a         benzothiophenylene group, a dibenzofuranylene group, a         dibenzothiophenylene group, a benzocarbazolylene group, a         dibenzocarbazolylene group, a dibenzosilolylene group, and a         pyridinylene group, each substituted with at least one selected         from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano         group, a nitro group, an amidino group, a hydrazino group, a         hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a         phenyl group, a biphenyl group, a terphenyl group, a naphthyl         group, a fluorenyl group, a spiro-bifluorenyl group, a         benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl         group, an anthracenyl group, a fluoranthenyl group, a         triphenylenyl group, a pyrenyl group, a chrysenyl group, a         perylenyl group, a pentaphenyl group, a hexacenyl group, a         pentacenyl group, a thiophenyl group, a furanyl group, a         carbazolyl group, an indolyl group, an isoindolyl group, a         benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl         group, a dibenzothiophenyl group, a benzocarbazolyl group, a         dibenzocarbazolyl group, a dibenzosilolyl group, and a pyridinyl         group.

In one or more embodiments, R₅₀₁ and R₅₀₂ in Formula 501 may each independently be selected from:

-   -   a phenyl group, a biphenyl group, a terphenyl group, a naphthyl         group, a fluorenyl group, a spiro-bifluorenyl group, a         benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl         group, an anthracenyl group, a fluoranthenyl group, a         triphenylenyl group, a pyrenyl group, a chrysenyl group, a         perylenyl group, a pentaphenyl group, a hexacenyl group, a         pentacenyl group, a thiophenyl group, a furanyl group, a         carbazolyl group, an indolyl group, an isoindolyl group, a         benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl         group, a dibenzothiophenyl group, a benzocarbazolyl group, a         dibenzocarbazolyl group, a dibenzosilolyl group, and a pyridinyl         group; and     -   a phenyl group, a biphenyl group, a terphenyl group, a naphthyl         group, a fluorenyl group, a spiro-bifluorenyl group, a         benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl         group, an anthracenyl group, a fluoranthenyl group, a         triphenylenyl group, a pyrenyl group, a chrysenyl group, a         perylenyl group, a pentaphenyl group, a hexacenyl group, a         pentacenyl group, a thiophenyl group, a furanyl group, a         carbazolyl group, an indolyl group, an isoindolyl group, a         benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl         group, a dibenzothiophenyl group, a benzocarbazolyl group, a         dibenzocarbazolyl group, a dibenzosilolyl group, and a pyridinyl         group, each substituted with at least one selected from         deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a         nitro group, an amidino group, a hydrazino group, a hydrazono         group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl         group, a biphenyl group, a terphenyl group, a naphthyl group, a         fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl         group, a dibenzofluorenyl group, a phenanthrenyl group, an         anthracenyl group, a fluoranthenyl group, a triphenylenyl group,         a pyrenyl group, a chrysenyl group, a perylenyl group, a         pentaphenyl group, a hexacenyl group, a pentacenyl group, a         thiophenyl group, a furanyl group, a carbazolyl group, an         indolyl group, an isoindolyl group, a benzofuranyl group, a         benzothiophenyl group, a dibenzofuranyl group, a         dibenzothiophenyl group, a benzocarbazolyl group, a         dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl         group, and —Si(Q₃₁)(Q₃₂)(Q₃₃), and     -   Q₃₁ to Q₃₃ may each independently be selected from a C₁-C₁₀         alkyl group, a C₁-C₁ alkoxy group, a phenyl group, a biphenyl         group, a terphenyl group, and a naphthyl group.

In one or more embodiments, xd4 in Formula 501 may be 2, but embodiments of the present disclosure are not limited thereto.

For example, the fluorescent dopant may be selected from Compounds FD1 to FD22:

In one or more embodiments, the fluorescent dopant may be selected from the following compounds, but embodiments of the present disclosure are not limited thereto.

Electron Transport Region in Organic Layer 150

The electron transport region may have i) a single-layered structure including a single layer including a single material, ii) a single-layered structure including a single layer including a plurality of different materials, or iii) a multi-layered structure having a plurality of layers including a plurality of different materials.

The electron transport region may include at least one selected from a buffer layer, a hole blocking layer, an electron control layer, an electron transport layer, and an electron injection layer, but embodiments of the present disclosure are not limited thereto.

For example, the electron transport region may have an electron transport layer/electron injection layer structure, a hole blocking layer/electron transport layer/electron injection layer structure, an electron control layer/electron transport layer/electron injection layer structure, or a buffer layer/electron transport layer/electron injection layer structure, wherein for each structure, constituting layers are sequentially stacked from an emission layer. However, embodiments of the structure of the electron transport region are not limited thereto.

The electron transport region (for example, a buffer layer, a hole blocking layer, an electron control layer, or an electron transport layer in the electron transport region) may include a metal-free compound containing at least one π electron-depleted nitrogen-containing ring.

The term “π electron-depleted nitrogen-containing ring,” as used herein, refers to a C₁-C₆₀ heterocyclic group having at least one *—N=*′ moiety as a ring-forming moiety.

For example, the “π electron-depleted nitrogen-containing ring” may be i) a 5-membered to 7-membered heteromonocyclic group having at least one *—N═*′ moiety, ii) a heteropolycyclic group in which two or more 5-membered to 7-membered heteromonocyclic groups each having at least one *—N═*′ moiety are condensed with each other (e.g., combined together), or iii) a heteropolycyclic group in which at least one of 5-membered to 7-membered heteromonocyclic groups, each having at least one *—N═*′ moiety, is condensed with (e.g., combined with) at least one C₅-C₆₀ carbocyclic group.

Examples of the π electron-depleted nitrogen-containing ring include an imidazole, a pyrazole, a thiazole, an isothiazole, an oxazole, an isoxazole, a pyridine, a pyrazine, a pyrimidine, a pyridazine, an indazole, a purine, a quinoline, an isoquinoline, a benzoquinoline, a phthalazine, a naphthyridine, a quinoxaline, a quinazoline, a cinnoline, a phenanthridine, an acridine, a phenanthroline, a phenazine, a benzimidazole, an isobenzothiazole, a benzoxazole, an isobenzoxazole, a triazole, a tetrazole, an oxadiazole, a triazine, thiadiazole, an imidazopyridine, an imidazopyrimidine, and an azacarbazole, but are not limited thereto.

For example, the electron transport region may include a compound represented by Formula 601:

[Ar₆₀₁]_(xe11)-[(L₆₀₁)_(xe1)-R₆₀₁]_(xe21).  Formula 601

In Formula 601,

-   -   Ar₆₀₁ may be a substituted or unsubstituted C₅-C₆₀ carbocyclic         group or a substituted or unsubstituted C₁-C₆₀ heterocyclic         group,     -   xe11 may be 1, 2, or 3,     -   L₆₀₁ may be selected from a substituted or unsubstituted C₃-C₁₀         cycloalkylene group, a substituted or unsubstituted C₁-C₁         heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀         cycloalkenylene group, a substituted or unsubstituted C₁-C₁         heterocycloalkenylene group, a substituted or unsubstituted         C₆-C₆₀ arylene group, a substituted or unsubstituted C₁-C₆₀         heteroarylene group, a substituted or unsubstituted divalent         non-aromatic condensed polycyclic group, and a substituted or         unsubstituted divalent non-aromatic condensed heteropolycyclic         group,     -   xe1 may be an integer from 0 to 5,     -   R₆₀₁ may be selected from a substituted or unsubstituted C₃-C₁₀         cycloalkyl group, a substituted or unsubstituted C₁-C₁         heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀         cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀         heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀         aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group,         a substituted or unsubstituted C₆-C₆₀ arylthio group, a         substituted or unsubstituted C₁-C₆₀ heteroaryl group, a         substituted or unsubstituted monovalent non-aromatic condensed         polycyclic group, a substituted or unsubstituted monovalent         non-aromatic condensed heteropolycyclic group,         —Si(Q₆₀₁)(Q₆₀₂)(Q₆₀₃), —C(═O)(Q₆₀₁), —S(═O)₂(Q₆₀₁), and         —P(═O)(Q₆₀₁)(Q₆₀₂),     -   Q₆₀₁ to Q₆₀₃ may each independently be a C₁-C₁₀ alkyl group, a         C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, a         terphenyl group, or a naphthyl group, and     -   xe21 may be an integer from 1 to 5.

In one embodiment, at least one of Ar₆₀₁(s) in the number of xe11 and R₆₀₁(s) in the number of xe21 may include the π electron-depleted nitrogen-containing ring.

In one embodiment, ring Ar₆₀₁ in Formula 601 may be selected from:

-   -   a benzene group, a naphthalene group, a fluorene group, a         spiro-bifluorene group, a benzofluorene group, a dibenzofluorene         group, a phenalene group, a phenanthrene group, an anthracene         group, a fluoranthene group, a triphenylene group, a pyrene         group, a chrysene group, a naphthacene group, a picene group, a         perylene group, a pentaphene group, an indenoanthracene group, a         dibenzofuran group, a dibenzothiophene group, a carbazole group,         an imidazole group, a pyrazole group, a thiazole group, an         isothiazole group, an oxazole group, an isoxazole group, a         pyridine group, a pyrazine group, a pyrimidine group, a         pyridazine group, an indazole group, a purine group, a quinoline         group, an isoquinoline group, a benzoquinoline group, a         phthalazine group, a naphthyridine group, a quinoxaline group, a         quinazoline group, a cinnoline group, a phenanthridine group, an         acridine group, a phenanthroline group, a phenazine group, a         benzimidazole group, an isobenzothiazole group, a benzoxazole         group, an isobenzoxazole group, a triazole group, a tetrazole         group, an oxadiazole group, a triazine group, a thiadiazole         group, an imidazopyridine group, an imidazopyrimidine group, and         an azacarbazole group; and     -   a benzene group, a naphthalene group, a fluorene group, a         spiro-bifluorene group, a benzofluorene group, a dibenzofluorene         group, a phenalene group, a phenanthrene group, an anthracene         group, a fluoranthene group, a triphenylene group, a pyrene         group, a chrysene group, a naphthacene group, a picene group, a         perylene group, a pentaphene group, an indenoanthracene group, a         dibenzofuran group, a dibenzothiophene group, a carbazole group,         an imidazole group, a pyrazole group, a thiazole group, an         isothiazole group, an oxazole group, an isoxazole group, a         pyridine group, a pyrazine group, a pyrimidine group, a         pyridazine group, an indazole group, a purine group, a quinoline         group, an isoquinoline group, a benzoquinoline group, a         phthalazine group, a naphthyridine group, a quinoxaline group, a         quinazoline group, a cinnoline group, a phenanthridine group, an         acridine group, a phenanthroline group, a phenazine group, a         benzimidazole group, an isobenzothiazole group, a benzoxazole         group, an isobenzoxazole group, a triazole group, a tetrazole         group, an oxadiazole group, a triazine group, a thiadiazole         group, an imidazopyridine group, an imidazopyrimidine group, and         an azacarbazole group, each substituted with at least one         selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a         cyano group, a nitro group, an amidino group, a hydrazino group,         a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group,         a phenyl group, a biphenyl group, a terphenyl group, a naphthyl         group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),         and     -   Q₃₁ to Q₃₃ may each independently be selected from a C₁-C₁₀         alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl         group, a terphenyl group, and a naphthyl group.

When xe11 in Formula 601 is two or more, two or more Ar₆₀₁(s) may be linked via a single bond.

In one or more embodiments, Ar₆₀₁ in Formula 601 may be an anthracene group.

In one or more embodiments, a compound represented by Formula 601 may be represented by Formula 601-1:

In Formula 601-1,

-   -   X₆₁₄ may be N or C(R₆₁₄), X₆₁₅ may be N or C(R₆₁₅), X₆₁₆ may be         N or C(R₆₁₆), and at least one selected from X₆₁₄ to X₆₁₆ may be         N,     -   L₆₁₁ to L₆₁₃ may each independently be the same as described in         connection with L₆₀₁,     -   xe611 to xe613 may each independently be defined the same as         xe1,     -   R₆₁₁ to R₆₁₃ may each independently be defined the same as R₆₀₁,         and     -   R₆₁₄ to R₆₁₆ may each independently be selected from hydrogen,         deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a         nitro group, an amidino group, a hydrazino group, a hydrazono         group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl         group, a biphenyl group, a terphenyl group, and a naphthyl         group.

In one embodiment, L₆₀₁ and L₆₁₁ to L₆₁₃ in Formulae 601 and 601-1 may each independently be selected from:

-   -   a phenylene group, a naphthylene group, a fluorenylene group, a         spiro-bifluorenylene group, a benzofluorenylene group, a         dibenzofluorenylene group, a phenanthrenylene group, an         anthracenylene group, a fluoranthenylene group, a         triphenylenylene group, a pyrenylene group, a chrysenylene         group, a perylenylene group, a pentaphenylene group, a         hexacenylene group, a pentacenylene group, a thiophenylene         group, a furanylene group, a carbazolylene group, an indolylene         group, an isoindolylene group, a benzofuranylene group, a         benzothiophenylene group, a dibenzofuranylene group, a         dibenzothiophenylene group, a benzocarbazolylene group, a         dibenzocarbazolylene group, a dibenzosilolylene group, a         pyridinylene group, an imidazolylene group, a pyrazolylene         group, a thiazolylene group, an isothiazolylene group, an         oxazolylene group, an isoxazolylene group, a thiadiazolylene         group, an oxadiazolylene group, a pyrazinylene group, a         pyrimidinylene group, a pyridazinylene group, a triazinylene         group, a quinolinylene group, an isoquinolinylene group, a         benzoquinolinylene group, a phthalazinylene group, a         naphthyridinylene group, a quinoxalinylene group, a         quinazolinylene group, a cinnolinylene group, a         phenanthridinylene group, an acridinylene group, a         phenanthrolinylene group, a phenazinylene group, a         benzimidazolylene group, an isobenzothiazolylene group, a         benzoxazolylene group, an isobenzoxazolylene group, a         triazolylene group, a tetrazolylene group, an         imidazopyridinylene group, an imidazopyrimidinylene group, and         an azacarbazolylene group; and     -   a phenylene group, a naphthylene group, a fluorenylene group, a         spiro-bifluorenylene group, a benzofluorenylene group, a         dibenzofluorenylene group, a phenanthrenylene group, an         anthracenylene group, a fluoranthenylene group, a         triphenylenylene group, a pyrenylene group, a chrysenylene         group, a perylenylene group, a pentaphenylene group, a         hexacenylene group, a pentacenylene group, a thiophenylene         group, a furanylene group, a carbazolylene group, an indolylene         group, an isoindolylene group, a benzofuranylene group, a         benzothiophenylene group, a dibenzofuranylene group, a         dibenzothiophenylene group, a benzocarbazolylene group, a         dibenzocarbazolylene group, a dibenzosilolylene group, a         pyridinylene group, an imidazolylene group, a pyrazolylene         group, a thiazolylene group, an isothiazolylene group, an         oxazolylene group, an isoxazolylene group, a thiadiazolylene         group, an oxadiazolylene group, a pyrazinylene group, a         pyrimidinylene group, a pyridazinylene group, a triazinylene         group, a quinolinylene group, an isoquinolinylene group, a         benzoquinolinylene group, a phthalazinylene group, a         naphthyridinylene group, a quinoxalinylene group, a         quinazolinylene group, a cinnolinylene group, a         phenanthridinylene group, an acridinylene group, a         phenanthrolinylene group, a phenazinylene group, a         benzimidazolylene group, an isobenzothiazolylene group, a         benzoxazolylene group, an isobenzoxazolylene group, a         triazolylene group, a tetrazolylene group, an         imidazopyridinylene group, an imidazopyrimidinylene group, and         an azacarbazolylene group, each substituted with at least one         selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a         cyano group, a nitro group, an amidino group, a hydrazino group,         a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group,         a phenyl group, a biphenyl group, a terphenyl group, a naphthyl         group, a fluorenyl group, a spiro-bifluorenyl group, a         benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl         group, an anthracenyl group, a fluoranthenyl group, a         triphenylenyl group, a pyrenyl group, a chrysenyl group, a         perylenyl group, a pentaphenyl group, a hexacenyl group, a         pentacenyl group, a thiophenyl group, a furanyl group, a         carbazolyl group, an indolyl group, an isoindolyl group, a         benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl         group, a dibenzothiophenyl group, a benzocarbazolyl group, a         dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl         group, an imidazolyl group, a pyrazolyl group, a thiazolyl         group, an isothiazolyl group, an oxazolyl group, an isoxazolyl         group, a thiadiazolyl group, an oxadiazolyl group, a pyrazinyl         group, a pyrimidinyl group, a pyridazinyl group, a triazinyl         group, a quinolinyl group, an isoquinolinyl group, a         benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl         group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl         group, a phenanthridinyl group, an acridinyl group, a         phenanthrolinyl group, a phenazinyl group, a benzimidazolyl         group, an isobenzothiazolyl group, a benzoxazolyl group, an         isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an         imidazopyridinyl group, an imidazopyrimidinyl group, and an         azacarbazolyl group,     -   but embodiments of the present disclosure are not limited         thereto.

In one or more embodiments, xe1 and xe611 to xe613 in Formulae 601 and 601-1 may each independently be 0, 1, or 2.

In one or more embodiments, in Formulae 601 and 601-1, R₆₀₁ and R₆₁₁ to R₆₁₃ may each independently be selected from:

-   -   a phenyl group, a biphenyl group, a terphenyl group, a naphthyl         group, a fluorenyl group, a spiro-bifluorenyl group, a         benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl         group, an anthracenyl group, a fluoranthenyl group, a         triphenylenyl group, a pyrenyl group, a chrysenyl group, a         perylenyl group, a pentaphenyl group, a hexacenyl group, a         pentacenyl group, a thiophenyl group, a furanyl group, a         carbazolyl group, an indolyl group, an isoindolyl group, a         benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl         group, a dibenzothiophenyl group, a benzocarbazolyl group, a         dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl         group, an imidazolyl group, a pyrazolyl group, a thiazolyl         group, an isothiazolyl group, an oxazolyl group, an isoxazolyl         group, a thiadiazolyl group, an oxadiazolyl group, a pyrazinyl         group, a pyrimidinyl group, a pyridazinyl group, a triazinyl         group, a quinolinyl group, an isoquinolinyl group, a         benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl         group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl         group, a phenanthridinyl group, an acridinyl group, a         phenanthrolinyl group, a phenazinyl group, a benzimidazolyl         group, an isobenzothiazolyl group, a benzoxazolyl group, an         isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an         imidazopyridinyl group, an imidazopyrimidinyl group, and an         azacarbazolyl group;     -   a phenyl group, a biphenyl group, a terphenyl group, a naphthyl         group, a fluorenyl group, a spiro-bifluorenyl group, a         benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl         group, an anthracenyl group, a fluoranthenyl group, a         triphenylenyl group, a pyrenyl group, a chrysenyl group, a         perylenyl group, a pentaphenyl group, a hexacenyl group, a         pentacenyl group, a thiophenyl group, a furanyl group, a         carbazolyl group, an indolyl group, an isoindolyl group, a         benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl         group, a dibenzothiophenyl group, a benzocarbazolyl group, a         dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl         group, an imidazolyl group, a pyrazolyl group, a thiazolyl         group, an isothiazolyl group, an oxazolyl group, an isoxazolyl         group, a thiadiazolyl group, an oxadiazolyl group, a pyrazinyl         group, a pyrimidinyl group, a pyridazinyl group, a triazinyl         group, a quinolinyl group, an isoquinolinyl group, a         benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl         group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl         group, a phenanthridinyl group, an acridinyl group, a         phenanthrolinyl group, a phenazinyl group, a benzimidazolyl         group, an isobenzothiazolyl group, a benzoxazolyl group, an         isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an         imidazopyridinyl group, an imidazopyrimidinyl group, and an         azacarbazolyl group, each substituted with at least one selected         from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano         group, a nitro group, an amidino group, a hydrazino group, a         hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a         phenyl group, a biphenyl group, a terphenyl group, a naphthyl         group, a fluorenyl group, a spiro-bifluorenyl group, a         benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl         group, an anthracenyl group, a fluoranthenyl group, a         triphenylenyl group, a pyrenyl group, a chrysenyl group, a         perylenyl group, a pentaphenyl group, a hexacenyl group, a         pentacenyl group, a thiophenyl group, a furanyl group, a         carbazolyl group, an indolyl group, an isoindolyl group, a         benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl         group, a dibenzothiophenyl group, a benzocarbazolyl group, a         dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl         group, an imidazolyl group, a pyrazolyl group, a thiazolyl         group, an isothiazolyl group, an oxazolyl group, an isoxazolyl         group, a thiadiazolyl group, an oxadiazolyl group, a pyrazinyl         group, a pyrimidinyl group, a pyridazinyl group, a triazinyl         group, a quinolinyl group, an isoquinolinyl group, a         benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl         group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl         group, a phenanthridinyl group, an acridinyl group, a         phenanthrolinyl group, a phenazinyl group, a benzimidazolyl         group, an isobenzothiazolyl group, a benzoxazolyl group, an         isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an         imidazopyridinyl group, an imidazopyrimidinyl group, and an         azacarbazolyl group; and     -   S(═O)₂(Q₆₀₁) and —P(═O)(Q₆₀₁)(Q₆₀₂), and     -   Q₆₀₁ and Q₆₀₂ may each independently be the same as described         above.

The electron transport region may include at least one compound selected from Compounds ET1 to ET36, but embodiments of the present disclosure are not limited thereto:

In one or more embodiments, the electron transport region may include at least one selected from 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), 4,7-diphenyl-1,10-phenanthroline (Bphen), Alq3, BAlq, 3-(biphenyl-4-yl)-5-(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole (TAZ), and NTAZ.

Thicknesses of the buffer layer, the hole blocking layer, and the electron control layer may each be in a range of about 20 Å to about 1,000 Å, for example, about 30 Å to about 300 Å. When the thicknesses of the buffer layer, the hole blocking layer, and the electron control layer are within these ranges, the electron transport region may have excellent hole blocking characteristics or electron control characteristics without a substantial increase in driving voltage.

A thickness of the electron transport layer may be in a range of about 100 Å to about 1,000 Å, for example, about 150 Å to about 500 Å. When the thickness of the electron transport layer is within the range described above, the electron transport layer may have suitable or satisfactory electron transport characteristics without a substantial increase in driving voltage.

The electron transport region (for example, the electron transport layer in the electron transport region) may further include, in addition to the materials described above, a metal-containing material.

The metal-containing material may include at least one selected from alkali metal complex and alkaline earth-metal complex. The alkali metal complex may include a metal ion selected from a L₁ ion, a Na ion, a K ion, a R_(b) ion, and a Cs ion, and the alkaline earth-metal complex may include a metal ion selected from a Be ion, a Mg ion, a Ca ion, a Sr ion, and a Ba ion. A ligand coordinated with the metal ion of the alkali metal complex or the alkaline earth-metal complex may be selected from hyroxy quinoline, hyroxy isoquinoline, hyroxy benzoquinoline, hyroxy acridine, hyroxy phenanthridine, hyroxy phenyloxazole, hyroxy phenylthiazole, hyroxy diphenyloxadiazole, hyroxy diphenylthiadiazole, hyroxy phenylpyridine, hyroxy phenylbenzimidazole, hyroxy phenylbenzothiazole, a bipyridine, a phenanthroline, and a cyclopentadiene, but embodiments of the present disclosure are not limited thereto.

For example, the metal-containing material may include a Li complex. The Li complex may include, for example, Compound ET-D1 (lithium quinolate, LiQ) or ET-D2.

The electron transport region may include an electron injection layer that facilitates injection of electrons from the second electrode 190. The electron injection layer may directly contact the second electrode 190.

The electron injection layer may have i) a single-layered structure including a single layer including a single material, ii) a single-layered structure including a single layer including a plurality of different materials, or iii) a multi-layered structure having a plurality of layers including a plurality of different materials.

The electron injection layer may include an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal compound, an alkaline earth-metal compound, a rare earth metal compound, an alkali metal complex, an alkaline earth-metal complex, a rare earth metal complex, or any combinations thereof.

The alkali metal may be selected from Li, Na, K, R_(b), and Cs. In one embodiment, the alkali metal may be Li, Na, or Cs. In one or more embodiments, the alkali metal may be L₁ or Cs, but embodiments of the present disclosure are not limited thereto.

The alkaline earth metal may be selected from Mg, Ca, Sr, and Ba.

The rare earth metal may be selected from Sc, Y, Ce, Tb, Yb, and Gd.

The alkali metal compound, the alkaline earth-metal compound, and the rare earth metal compound may be selected from oxides and halides (for example, fluorides, chlorides, bromides, or iodides) of the alkali metal, the alkaline earth-metal, and the rare earth metal.

The alkali metal compound may be selected from alkali metal oxides, such as Li₂O, Cs₂O, or K₂O, and alkali metal halides, such as LiF, NaF, CsF, KF, LiI, NaI, CsI, or KI. In one embodiment, the alkali metal compound may be selected from LiF, Li₂O, NaF, LiI, NaI, CsI, and KI, but embodiments of the present disclosure are not limited thereto.

The alkaline earth-metal compound may be selected from alkaline earth-metal oxides, such as BaO, SrO, CaO, BaxSr_(1-x)O (0<x<1), or BaxCa_(1-x)O (0<x<1). In one embodiment, the alkaline earth-metal compound may be selected from BaO, SrO, and CaO, but embodiments of the present disclosure are not limited thereto.

The rare earth metal compound may be selected from YbF₃, ScF₃, Sc₂O₃, Y₂O₃, Ce₂O₃, GdF₃, and TbF₃. In one embodiment, the rare earth metal compound may be selected from YbF₃, ScF₃, TbF₃, YbI₃, ScI₃, and TbI₃, but embodiments of the present disclosure are not limited thereto.

The alkali metal complex, the alkaline earth-metal complex, and the rare earth metal complex may include an ion of alkali metal, alkaline earth-metal, and rare earth metal as described above, and a ligand coordinated with a metal ion of the alkali metal complex, the alkaline earth-metal complex, or the rare earth metal complex may be selected from hydroxy quinoline, hydroxy isoquinoline, hydroxy benzoquinoline, hydroxy acridine, hydroxy phenanthridine, hydroxy phenyloxazole, hydroxy phenylthiazole, hydroxy diphenyloxadiazole, hydroxy diphenylthiadiazol, hydroxy phenylpyridine, hydroxy phenylbenzimidazole, hydroxy phenylbenzothiazole, bipyridine, phenanthroline, and cyclopentadiene, but embodiments of the present disclosure are not limited thereto.

The electron injection layer may consist of an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal compound, an alkaline earth-metal compound, a rare earth metal compound, an alkali metal complex, an alkaline earth-metal complex, a rare earth metal complex, or any combinations thereof, as described above. In one or more embodiments, the electron injection layer may further include an organic material. When the electron injection layer further includes an organic material, an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal compound, an alkaline earth-metal compound, a rare earth metal compound, an alkali metal complex, an alkaline earth-metal complex, a rare earth metal complex, or any combinations thereof may be homogeneously or non-homogeneously dispersed in a matrix including the organic material.

A thickness of the electron injection layer may be in a range of about 1 Å to about 100 Å, for example, about 3 Å to about 90 Å. When the thickness of the electron injection layer is within the range described above, the electron injection layer may have suitable or satisfactory electron injection characteristics without a substantial increase in driving voltage.

Second Electrode 190

The second electrode 190 may be located on the organic layer 150 having such a structure. The second electrode 190 may be a cathode which is an electron injection electrode, and in this regard, a material for forming the second electrode 190 may be selected from metal, an alloy, an electrically conductive compound, and a combination thereof, which have a relatively low work function.

The second electrode 190 may include at least one selected from lithium (Li), silver (Ag), magnesium (Mg), aluminum (AI), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), magnesium-silver (Mg—Ag), ITO, and IZO, but embodiments of the present disclosure are not limited thereto. The second electrode 190 may be a transmissive electrode, a semi-transmissive electrode, or a reflective electrode.

The second electrode 190 may have a single-layered structure, or a multi-layered structure including two or more layers.

Description of FIGS. 2-4

An organic light-emitting device 20 of FIG. 2 includes a first capping layer 210, a first electrode 110, an organic layer 150, and a second electrode 190 which are sequentially stacked in this stated order, an organic light-emitting device 30 of FIG. 3 includes a first electrode 110, an organic layer 150, a second electrode 190, and a second capping layer 220 which are sequentially stacked in this stated order, and an organic light-emitting device 40 of FIG. 4 includes a first capping layer 210, a first electrode 110, an organic layer 150, a second electrode 190, and a second capping layer 220.

Regarding FIGS. 2-4 , the first electrode 110, the organic layer 150, and the second electrode 190 may be understood by referring to the description presented in connection with FIG. 1 .

In the organic layer 150 of each of the organic light-emitting devices 20 and 40, light generated in an emission layer may pass through the first electrode 110, which is a semi-transmissive electrode or a transmissive electrode, and the first capping layer 210 toward the outside, and in the organic layer 150 of each of the organic light-emitting devices 30 and 40, light generated in an emission layer may pass through the second electrode 190, which is a semi-transmissive electrode or a transmissive electrode, and the second capping layer 220 toward the outside.

The first capping layer 210 and the second capping layer 220 may increase external luminescent efficiency according to the principle of constructive interference.

The first capping layer 210 and the second capping layer 220 may each independently be an organic capping layer including an organic material, an inorganic capping layer including an inorganic material, or a composite capping layer including an organic material and an inorganic material.

At least one selected from the first capping layer 210 and the second capping layer 220 may each independently include at least one material selected from carbocyclic compounds, heterocyclic compounds, amine-based compounds, porphyrine derivatives, phthalocyanine derivatives, a naphthalocyanine derivatives, alkali metal complexes, and alkaline earth metal complexes. The carbocyclic compound, the heterocyclic compound, and the amine-based compound may be optionally substituted with a substituent containing at least one element selected from O, N, S, Se, Si, F, Cl, Br, and I. In one embodiment, at least one selected from the first capping layer 210 and the second capping layer 220 may each independently include an amine-based compound.

In one embodiment, at least one selected from the first capping layer 210 and the second capping layer 220 may each independently include the compound represented by Formula 201 or the compound represented by Formula 202.

In one or more embodiments, at least one selected from the first capping layer 210 and the second capping layer 220 may each independently include a compound selected from Compounds HT28 to HT33 and Compounds CP1 to CP5, but embodiments of the present disclosure are not limited thereto.

Hereinbefore, the organic light-emitting device according to an embodiment has been described in connection with FIGS. 1-4 . However, embodiments of the present disclosure are not limited thereto.

Layers constituting the hole transport region, an emission layer, and layers constituting the electron transport region may be formed in a certain region by using one or more suitable methods selected from vacuum deposition, spin coating, casting, Langmuir-Blodgett (LB) deposition, ink-jet printing, laser-printing, and laser-induced thermal imaging.

When layers constituting the hole transport region, an emission layer, and layers constituting the electron transport region are formed by vacuum deposition, the vacuum deposition may be performed at a deposition temperature of about 100° C. to about 500° C., a vacuum degree of about 10⁻⁸ torr to about 10⁻³ torr, and a deposition speed of about 0.01 Å/sec to about 100 Å/sec by taking into account a material to be included in a layer to be formed, and the structure of a layer to be formed.

When layers constituting the hole transport region, an emission layer, and layers constituting the electron transport region are formed by spin coating, the spin coating may be performed at a coating speed of about 2,000 rpm to about 5,000 rpm and at a heat treatment temperature of about 80° C. to about 200° C. by taking into account a material to be included in a layer to be formed, and the structure of a layer to be formed.

General Definition of at Least Some of the Substituents

The term “C₁-C₆₀ alkyl group,” as used herein, refers to a linear or branched aliphatic saturated hydrocarbon monovalent group having 1 to 60 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, an isoamyl group, and a hexyl group. The term “C₁-C₆₀ alkylene group,” as used herein, refers to a divalent group having substantially the same structure as the C₁-C₆₀ alkyl group.

The term “C₂-C₆₀ alkenyl group,” as used herein, refers to a hydrocarbon group having at least one double bond at a main chain (e.g., in the middle) or at the terminus (e.g., a terminal end) of the C₂-C₆₀ alkyl group, and examples thereof include an ethenyl group, a propenyl group, and a butenyl group. The term “C₂-C₆₀ alkenylene group,” as used herein, refers to a divalent group having substantially the same structure as the C₂-C₆₀ alkenyl group.

The term “C₂-C₆₀ alkynyl group,” as used herein, refers to a hydrocarbon group having at least one triple bond at a main chain (e.g., in the middle) or at the terminus (e.g., at a terminal end) of the C₂-C₆₀ alkyl group, and examples thereof include an ethynyl group, and a propynyl group. The term “C₂-C₆₀ alkynylene group,” as used herein, refers to a divalent group having substantially the same structure as the C₂-C₆₀ alkynyl group.

The term “C₁-C₆₀ alkoxy group,” as used herein, refers to a monovalent group represented by —OA₁₀₁ (wherein A₁₀₁ is the C₁-C₆₀ alkyl group), and examples thereof include a methoxy group, an ethoxy group, and an isopropyloxy group.

The term “C₃-C₁₀ cycloalkyl group,” as used herein, refers to a monovalent saturated hydrocarbon monocyclic group having 3 to 10 carbon atoms, and examples thereof include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a cycloheptyl group. The term “C₃-C₁₀ cycloalkylene group,” as used herein, refers to a divalent group having substantially the same structure as the C₃-C₁₀ cycloalkyl group.

The term “C₁-C₁₀ heterocycloalkyl group,” as used herein, refers to a monovalent monocyclic group having at least one heteroatom selected from N, O, Si, P, and S as a ring-forming atom and 1 to 10 carbon atoms, and examples thereof include a 1,2,3,4-oxatriazolidinyl group, a tetrahydrofuranyl group, and a tetrahydrothiophenyl group. The term “C₁-C₁₀ heterocycloalkylene group,” as used herein, refers to a divalent group having substantially the same structure as the C₁-C₁₀ heterocycloalkyl group.

The term “C₃-C₁₀ cycloalkenyl group,” as used herein, refers to a monovalent monocyclic group that has 3 to 10 carbon atoms and at least one double bond in a ring thereof and no aromaticity (e.g., the entire ring and/or group is not aromatic), and examples thereof include a cyclopentenyl group, a cyclohexenyl group, and a cycloheptenyl group. The term “C₃-C₁₀ cycloalkenylene group,” as used herein, refers to a divalent group having substantially the same structure as the C₃-C₁₀ cycloalkenyl group.

The term “C₁-C₁₀ heterocycloalkenyl group,” as used herein, refers to a monovalent monocyclic group that has at least one heteroatom selected from N, O, Si, P, and S as a ring-forming atom, 1 to 10 carbon atoms, and at least one double bond in its ring. Non-limiting examples of the C₁-C₁₀ heterocycloalkenyl group include a 4,5-dihydro-1,2,3,4-oxatriazolyl group, a 2,3-dihydrofuranyl group, and a 2,3-dihydrothiophenyl group. The term “C₁-C₁₀ heterocycloalkenylene group,” as used herein, refers to a divalent group having substantially the same structure as the C₁-C₁₀ heterocycloalkenyl group.

The term “C₆-C₆₀ aryl group,” as used herein, refers to a monovalent group having a carbocyclic aromatic system having 6 to 60 carbon atoms, and a C₆-C₆a arylene group used herein refers to a divalent group having a carbocyclic aromatic system having 6 to 60 carbon atoms. Non-limiting examples of the C₆-C₆₀ aryl group include a phenyl group, a naphthyl group, an anthracenyl group, a phenanthrenyl group, a pyrenyl group, and a chrysenyl group. When the C₆-C₆₀ aryl group and the C₆-C₆₀ arylene group each include two or more rings, the rings may be fused to each other (e.g., combined together).

The term “C₁-C₆₀ heteroaryl group,” as used herein, refers to a monovalent group having a carbocyclic aromatic system that has at least one heteroatom selected from N, O, Si, P, and S as a ring-forming atom, in addition to 1 to 60 carbon atoms. The term “C₁-C₆₀ heteroarylene group,” as used herein, refers to a divalent group having a carbocyclic aromatic system that has at least one heteroatom selected from N, O, Si, P, and S as a ring-forming atom, in addition to 1 to 60 carbon atoms. Non-limiting examples of the C₁-C₆₀ heteroaryl group include a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, and an isoquinolinyl group. When the C₁-C₆₀ heteroaryl group and the C₁-C₆₀ heteroarylene group each include two or more rings, the rings may be condensed with each other (e.g., combined together).

The term “C₆-C₆₀ aryloxy group,” as used herein, refers to —OA₁₀₂ (wherein A₁₀₂ is the C₆-C₆₀ aryl group), and the term “C₆-C₆₀ arylthio group,” as used herein, refers to —SA₁₀₃ (wherein A₁₀₃ is the C₆-C₆₀ aryl group).

The term “monovalent non-aromatic condensed polycyclic group,” as used herein, refers to a monovalent group having two or more rings condensed with each other (e.g., combined together), only carbon atoms (for example, having 8 to 60 carbon atoms) as ring-forming atoms, and no aromaticity in its entire molecular structure (e.g., the entire group and/or molecule is not aromatic). An example of the monovalent non-aromatic condensed polycyclic group is a fluorenyl group. The term “divalent non-aromatic condensed polycyclic group,” as used herein, refers to a divalent group having substantially the same structure as the monovalent non-aromatic condensed polycyclic group.

The term “monovalent non-aromatic condensed heteropolycyclic group,” as used herein, refers to a monovalent group having two or more rings condensed to each other (e.g., combined together), at least one heteroatom selected from N, O, Si, P, and S, other than carbon atoms (for example, having 1 to 60 carbon atoms), as a ring-forming atom, and no aromaticity in its entire molecular structure (e.g., the entire group and/or molecule is not aromatic). An example of the monovalent non-aromatic condensed heteropolycyclic group is a carbazolyl group. The term “divalent non-aromatic condensed heteropolycyclic group,” as used herein, refers to a divalent group having substantially the same structure as the monovalent non-aromatic condensed heteropolycyclic group.

The term “C₅-C₆₀ carbocyclic group,” as used herein, refers to a monocyclic or polycyclic group having 5 to 60 carbon atoms in which a ring-forming atom is a carbon atom only. The C₅-C₆₀ carbocyclic group may be an aromatic carbocyclic group or a non-aromatic carbocyclic group. The C₅-C₆₀ carbocyclic group may be a ring, such as benzene, a monovalent group, such as a phenyl group, or a divalent group, such as a phenylene group. In one or more embodiments, depending on the number of substituents connected to the C₅-C₆₀ carbocyclic group, the C₅-C₆₀ carbocyclic group may be a trivalent group or a quadrivalent group.

The term “C₁-C₆₀ heterocyclic group,” as used herein, refers to a monovalent monocyclic group that has substantially the same structure as the C₅-C₆₀ carbocyclic group and has at least one heteroatom selected from N, O, Si, P, and S as a ring-forming atom and 1 to 60 carbon atoms.

In the present specification, at least one substituent of the substituted C₅-C₆₀ carbocyclic group, the substituted C₁-C₆₀ heterocyclic group, the substituted C₁-C₂₀ alkylene group, the substituted C₂-C₂₀ alkenylene group, the substituted C₃-C₁a cycloalkylene group, the substituted C₁-C₁₀ heterocycloalkylene group, the substituted C₃-C₁₀ cycloalkenylene group, the substituted C₁-C₁₀ heterocycloalkenylene group, the substituted C₆-C₆₀ arylene group, the substituted C₁-C₆₀ heteroarylene group, the substituted divalent non-aromatic condensed polycyclic group, the substituted divalent non-aromatic condensed heteropolycyclic group, the substituted C₁-C₆₀ alkyl group, the substituted C₂-C₆₀ alkenyl group, the substituted C₂-C₆₀ alkynyl group, the substituted C₁-C₆₀ alkoxy group, the substituted C₃-C₁₀ cycloalkyl group, the substituted C₁-C₁₀ heterocycloalkyl group, the substituted C₃-C₁₀ cycloalkenyl group, the substituted C₁-C₁₀ heterocycloalkenyl group, the substituted C₆-C₆₀ aryl group, the substituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀ arylthio group, the substituted C₁-C₆₀ heteroaryl group, the substituted monovalent non-aromatic condensed polycyclic group, and the substituted monovalent non-aromatic condensed heteropolycyclic group may be selected from:

deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group;

-   -   a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl         group, and a C₁-C₆₀ alkoxy group, each substituted with at least         one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group,         a cyano group, a nitro group, an amidino group, a hydrazino         group, a hydrazono group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀         heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁         heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy         group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a         monovalent non-aromatic condensed polycyclic group, a monovalent         non-aromatic condensed heteropolycyclic group,         —Si(Q₄₁)(Q₄₂)(Q₄₃), —N(Q₄₁)(Q₄₂), —B(Q₄₁)(Q₄₂), —C(═O)(Q₄₁),         —S(═O)₂(Q₄₁), and —P(═O)(Q₄₁)(Q₄₂);     -   a C₃-C₁₀ cycloalkyl group, a C₁-C₁ heterocycloalkyl group, a         C₃-C₁₀ cycloalkenyl group, a C₁-C₁ heterocycloalkenyl group, a         C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio         group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic         condensed polycyclic group, and a monovalent non-aromatic         condensed heteropolycyclic group;     -   a C₃-C₁₀ cycloalkyl group, a C₁-C₁ heterocycloalkyl group, a         C₃-C₁₀ cycloalkenyl group, a C₁-C₁ heterocycloalkenyl group, a         C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio         group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic         condensed polycyclic group, and a monovalent non-aromatic         condensed heteropolycyclic group, each substituted with at least         one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group,         a cyano group, a nitro group, an amidino group, a hydrazino         group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl         group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀         cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀         cycloalkenyl group, a C₁-C₁ heterocycloalkenyl group, a C₆-C₆₀         aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a         C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed         polycyclic group, a monovalent non-aromatic condensed         heteropolycyclic group, —Si(Q₅₁)(Q₅₂)(Q₅₃), —N(Q₅₁)(Q₅₂),         —B(Q₅₁)(Q₅₂), —C(═O)(Q₅₁), —S(═O)₂(Q₅₁), and —P(═O)(Q₅₁)(Q₅₂);         and     -   —Si(Q₆₁)(Q₆₂)(Q₆₃), —N(Q₆₁)(Q₆₂), —B(Q₆₁)(Q₆₂), —C(═O)(Q₆₁),         —S(═O)₂(Q₆₁), and —P(═O)(Q₆₁)(Q₆₂), and     -   Q₄₁ to Q₄₃, Q₅₁ to Q₅₃, and Q₆₁ to Q₆₃ may each independently be         selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl         group, a cyano group, a nitro group, an amidino group, a         hydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a         C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy         group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl         group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl         group, a C₆-C₆₀ aryl group, a C₁-C₆₀ heteroaryl group, a         monovalent non-aromatic condensed polycyclic group, a monovalent         non-aromatic condensed heteropolycyclic group, a biphenyl group,         and a terphenyl group.

The term “Ph,” as used herein, refers to a phenyl group, the term “Me,” as used herein, refers to a methyl group, the term “Et,” as used herein, refers to an ethyl group, the term “ter-Bu” or “Bu^(t),” as used herein, refers to a tert-butyl group, and the term “OMe,” as used herein, refers to a methoxy group.

The term “biphenyl group,” as used herein, refers to “a phenyl group substituted with a phenyl group.” In other words, the “biphenyl group” is a substituted phenyl group having a C₆-C₆₀ aryl group as a substituent.

The term “terphenyl group,” as used herein, refers to “a phenyl group substituted with a biphenyl group.” In other words, the “terphenyl group” is a substituted phenyl group having, as a substituent, a C₆-C₆₀ aryl group substituted with a C₆-C₆₀ aryl group.

* and *′ as used herein, unless defined otherwise, each refer to a binding site to a neighboring atom in a corresponding formula.

Hereinafter, a compound according to embodiments and an organic light-emitting device according to embodiments will be described in more detail with reference to Synthesis Examples and Examples. The wording “B was used instead of A” used in describing Synthesis Examples refers to that an identical molar equivalent of B was used in place of an identical molar equivalent of A.

EXAMPLES Synthesis Example 1: Synthesis of Compound 3

Synthesis of Intermediate 3-1

Carbazole (2 eq.) was reacted with nBuLi (2 eq.) at 0° C. and then reacted with cyanuric chloride (1 eq.) to obtain Intermediate 3-1. Intermediate 3-1 was identified by liquid chromatography-mass spectrometry (LC-MS).

C₂₇H₁₆N₅Cl: M+1 445.1.

Synthesis of Compound 3

2.3 g of Intermediate 3-1, 2.4 g of (3-(triphenylsilyl)phenyl)boronic acid (CAS #=1253912-58-1), 0.24 g of tetrakis(triphenylphosphine)palladium, and 1.8 g of potassium carbonate were added to a reaction container, dissolved in 40 mL of toluene, 10 mL of ethanol, and 10 mL of distilled water, and then refluxed for 24 hours. After the reaction was completed, a reaction solution was extracted with ethyl acetate. A collected organic layer was dried by using anhydrous magnesium sulfate, and a solvent was evaporated therefrom. A residue obtained therefrom was separated and purified by silica gel column chromatography to obtain 1.6 g of Compound 3 (yield: 42%). Compound 3 was identified by LC-MS and ¹H-NMR.

Synthesis Example 2: Synthesis of Compound 4

Synthesis of Intermediate 4-1

3,4-di-tert-butyl-9H-carbazole (2 eq.) was reacted with nBuLi (2 eq.) at 0° C. and then reacted with cyanuric chloride (1 eq.) to obtain Intermediate 4-1. Intermediate 4-1 was identified by LC-MS.

C₄₃H_(48 Cl)N₅: M+1 670.34.

Synthesis of Compound 4

1.9 g of Intermediate 4-1, 1.95 g of (3-(triphenylsilyl)phenyl) boronic acid (CAS #=1253912-58-1), 0.20 g of tetrakis(triphenylphosphine)palladium, and 1.47 g of potassium carbonate were added to a reaction container, dissolved in 40 mL of toluene, 10 mL of ethanol, and 10 mL of distilled water, and then refluxed for 24 hours. After the reaction was completed, a reaction solution was extracted with ethyl acetate. A collected organic layer was dried by using anhydrous magnesium sulfate, and a solvent was evaporated therefrom. A residue obtained therefrom was separated and purified by silica gel column chromatography to obtain 2.28 g of Compound 4 (yield: 55%). Compound 4 was identified by LC-MS and ¹H-NMR.

Synthesis Example 3: Synthesis of Compound 8

Synthesis of Intermediate 8-1

(3-(triphenylsilyl)phenyl)boronic acid (CAS #=1253912-58-1) (2 eq.) was reacted with cyanuric chloride (1 eq.) at 120° C. in the presence of a Pd(PPh₃)₄ catalyst (0.05 eq.) to obtain Intermediate 8-1. Intermediate 8-1 was identified by LC-MS.

C₅₁H₃₈ClN₃Si₂: M+1 784.43.

Synthesis of Compound 8

3.3 g of Intermediate 8-1, 0.81 g of 9H-carbazole-3-carbonitrile (57102-93-9), 1.8 g of potassium phosphate, and 30 mL of dimethylformamide (DMF) were added to a reaction vessel and then refluxed at a temperature of 160° C. for 24 hours. After the reaction was completed, a reaction solution was extracted with ethyl acetate. A collected organic layer was dried by using magnesium sulfate, and a solvent was evaporated therefrom. A residue obtained therefrom was separated and purified by silica gel column chromatography to obtain 2.5 g of Compound 8 (yield: 62%). Compound 8 was identified by LC-MS and ¹H-NMR.

Synthesis Example 4: Synthesis of Compound 18

Synthesis of Intermediate 18-1

(3-bromophenyl)triphenylsilane (CAS #=185626-73-7) (1 eq.) was reacted with magnesium (1 eq.) at 0° C. and then reacted with cyanuric chloride (1 eq.) to obtain Intermediate 18-1. Intermediate 18-1 was identified by LC-MS.

C₂₇H₁₉Cl₂N₃Si: M+1 484.08.

Synthesis of Intermediate 18-2

1-(2-bromophenyl)dibenzo[b,d]furan (CAS #=1659313-53-7) (1 eq.) was reacted with nBuLi (1.2 eq.) and then reacted with trimethylborate (1.4 eq.) at −78 0° C. to obtain Intermediate 18-2. Intermediate 18-2 was identified by LC-MS.

C₁₈H₁₃BO₃: M+1 289.12.

Synthesis of Intermediate 18-3

Intermediate 18-1 (1 eq.) and Intermediate 18-2 (1.2 eq.) were Suzuki-coupled at 120° C. in the presence of a Pd(PPh₃)₄ catalyst (0.05 eq.) to obtain Intermediate 18-3. Intermediate 18-3 was identified by LC-MS.

C₄₅H₃₀ClN₃OSi: M+1 692.19.

Synthesis of Compound 18

1.9 g of Intermediate 18-3, 0.53 g of 9H-carbazole-3-carbonitrile (CAS #=57102-93-9), 1.2 g of potassium phosphate, and 20 mL of DMF were added to a reaction vessel and then refluxed at a temperature of 160° C. for 24 hours. After the reaction was completed, a reaction solution was extracted with ethyl acetate. A collected organic layer was dried by using anhydrous magnesium sulfate, and a solvent was evaporated therefrom. A residue obtained therefrom was separated and purified by silica gel column chromatography to obtain 1.4 g of Compound 18 (yield: 59%). Compound 18 was identified by LC-MS and ¹H-NMR.

Synthesis Example 5: Synthesis of Compound 22 Synthesis of Intermediate 22-1

2-(triphenylsilyl)-9H-carbazole (CAS #=1262866-95-4) (1 eq.) was reacted with nBuLi (1 eq.) and then reacted with 2,4-dichloro-6-phenyltriazine (CAS #=1700-02-3) (1 eq.) at −78° C. to obtain Intermediate 22-1. Intermediate 22-1 was identified by LC-MS.

C₃₉H₂₇ClN₄Si: M+1 615.18.

Synthesis of Compound 22

2.3 g of Intermediate 22-1, 1.71 g of (3-(triphenylsilyl)phenyl)boronic acid (CAS #=1253912-58-1), 0.17 g of tetrakis(triphenylphosphine)palladium, and 1.30 g of potassium carbonate were added to a reaction vessel, dissolved in 40 mL of toluene, 10 mL of ethanol, and 10 mL of distilled water, and then refluxed for 24 hours. After the reaction was completed, a reaction solution was extracted with ethyl acetate. A collected organic layer was dried by using anhydrous magnesium sulfate, and a solvent was evaporated therefrom. A residue obtained therefrom was separated and purified by silica gel column chromatography to obtain 1.95 g of Compound 22 (yield: 57%). Compound 22 was identified by LC-MS and ¹H-NMR.

Synthesis Example 6: Synthesis of Compound 53

Synthesis of Intermediate 53-1

(3-(triphenylsilyl)phenyl)boronic acid (CAS #=1253912-58-1) (2 eq.) was reacted with cyanuric chloride (1 eq.) at 120° C. in the presence of a Pd(PPh₃)₄ catalyst (0.05 eq.) to obtain Intermediate 53-1. Intermediate 53-1 was identified by LC-MS.

C₅₁H₃₈ClN₃Si₂: M+1 784.33.

Synthesis of Compound 53

2.9 g of Intermediate 53-1, 0.8 g of diphenylamine, 0.17 g of Pd₂dba₃, 0.1 mL of P(tBu)₃, and 1.1 g of sodium tert-butoxide were added to a reaction vessel, dissolved in 30 mL of toluene, and then refluxed for 24 hours. After the reaction was completed, a reaction solution was extracted with ethyl acetate. A collected organic layer was dried by using anhydrous magnesium sulfate, and a solvent was evaporated therefrom. A residue obtained therefrom was separated and purified by silica gel column chromatography to obtain 2.1 g of Compound 53 (yield: 49%). Compound 53 was identified by LC-MS and ¹H-NMR.

Synthesis Example 7: Synthesis of Compound 58

Synthesis of Intermediate 58-1

(3-bromophenyl)triphenylsilane (CAS #=185626-73-7) (1 eq.) was reacted with aniline (1.2 eq.) at 120° C. in the presence of a Pd₂dba₃ catalyst (0.05 eq.) to obtain Intermediate 58-1. Intermediate 58-1 was identified by LC-MS.

C₃₀H₂₅NSi: M+1 428.22.

Synthesis of Intermediate 58-2

Intermediate 58-1 (1 eq.) was reacted with 2,4-dichloro-6-phenyltriazine (CAS #=1700-02-3) (1 eq.) at 120° C. in the presence of a Pd₂dba₃ catalyst (0.05 eq.) to obtain Intermediate 58-2. Intermediate 58-2 was identified by LC-MS.

C₃₉H₂₉ClN₄Si: M+1 617.32.

Synthesis of Compound 58

3.4 g of Intermediate 58-2, 2.52 g of (3-(triphenylsilyl)phenyl)boronic acid (CAS #=1253912-58-1), 0.25 g of tetrakis(triphenylphosphine)palladium, 1.9 g of potassium carbonate were added to a reaction vessel, dissolved in 40 mL of toluene, 10 mL of ethanol, and 10 mL of distilled water, and then refluxed for 24 hours. After the reaction was completed, a reaction solution was extracted with ethyl acetate. A collected organic layer was dried by using anhydrous magnesium sulfate, and a solvent was evaporated therefrom. A residue obtained therefrom was separated and purified by silica gel column chromatography to obtain 3.08 g of Compound 58 (yield: 61%). Compound 58 was identified by LC-MS and ¹H-NMR.

¹H nuclear magnetic resonance spectroscopy (NMR) and fast atom bombardment-mass spectrometry)MS/FAB) of Compounds synthesized according to Synthesis Examples 1 to 7 are shown in Table 1.

Synthesis methods of compounds other than Compounds shown in Table 1 may also be readily recognized by those of ordinary skill in the art by referring to the synthesis mechanisms and source materials described herein above.

TABLE 1 MS/FAB Compound ¹H NMR (CDCl₃, 400 MHz) Found calc. 3 8.54 (d, 2H), 8.37 (d, 1H), 8.19 (d, 2H), 746.33 745.27 7.92 (d, 2H), 7.87 (s, 1H), 7.63 (t, 1H), 7.57-7.54 (m, 3H), 7.5 (t, 2H), 7.45-7.32 (m, 17H), 7.2 (t, 2H), 7.12 (t, 2H) 4 8.95(s, 2H), 8.37-8.32 (m, 3H), 7.87-7.82 970.69 969.52 (m, 3H), 7.65-7.60 (m, 2H), 7.55 (d, 1H), 7.49 (d, 2H), 7.45-7.32 (m, 15H), 7.11 (d, 2H), 1.43 (s, 12H) 8 8.54 (d, 1H), 8.36 (d, 2H), 7.93 (s, 2H), 940.28 939.32 7.88-7.74 (m, 2H), 7.76 (t, 2H), 7.56 (d, 2H), 7.45-7.32 (m, 30H), 7.29-7.22 (m, 2H), 7.12 (t, 1H) 18 8.55 (d, 1H), 8.3 (d, 1H), 7.98-7.90 (m, 848.33 847.28 4H), 7.82 (d, 1H), 7.8 (s, 1H), 7.72 (d, 1H), 7.67-7.50 (m, 7H), 7.44-7.40 (m, 7H), 7.32-7.22 (m, 20H), 7.11 (t, 1H) 22 8.55(d, 1H), 8.37-8.32 (m, 3H), 8.22 (d, 915.23 914.33 1H), 7.94 (d, 1H), 7.87 (s, 1H), 7.69-7.62 (m, 2H), 7.56 (d, 1H), 7.51-7.45 (m, 15H), 7.39-7.32 (m, 19H), 7.26 (t, 1H), 7.16 (t, 1H) 53 8.38(d, 1H), 7.87 (s, 1H), 7.62 (t, 1H), 917.33 916.34 7.56 (d, 1H), 7.46 (m, 12H), 7.38 (d, 18H), 7.22 (t, 4H), 7.09 (d, 4H), 6.99 (t, 2H) 58 8.38-8.32 (m, 3H), 7.88 (s, 1H), 7.62 (t, 917.29 916.34 1H), 7.52 (d, 1H), 7.50-7.35 (m, 34H), 7.30 (s, 1H), 7.24 (t, 2H), 7.17 (t, 1H), 7.12 (d, 1H), 7.05 (t, 1H)

Example 1

As an anode, a Corning 15 Ω/cm² (1,200 Å) indium tin oxide (ITO) glass substrate was cut to a size of 50 mm×50 mm×0.5 mm, sonicated with isopropyl alcohol and pure water each for 5 minutes, and then cleaned by exposure to ultraviolet rays and ozone for 30 minutes. The ITO glass substrate was provided to a vacuum deposition apparatus.

An available material, N,N′-di(1-naphthyl)-N,N′-diphenylbenzidine (NPB), was vacuum-deposited on the ITO glass substrate to form a hole injection layer having a thickness of 300 Å, and a hole transport compound mCP was vacuum-deposited on the hole injection layer to form a hole transport layer having a thickness of 200 Å.

As a host, Compound 3 and a phosphorescent dopant PD26 were co-deposited on the hole transport layer at a weight ratio of 92:8 to form an emission layer having a thickness of 250 Å.

Then, 3-(4-biphenylyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole (TAZ) was deposited on the emission layer to form an electron transport layer having a thickness of 200 Å, an alkali metal halide LiF was deposited on the electron transport layer to form an electron injection layer having a thickness of 10 Å, and Al was vacuum-deposited on the electron injection layer to form an LiF/Al electrode having a thickness of 100 Å, thereby completing the manufacture of an organic light-emitting device.

Examples 2 to 7

Organic light-emitting devices were manufactured in substantially the same manner as in Example 1, except that Compounds shown in Table 2 were each used instead of Compound 3 in forming an emission layer.

Comparative Examples 1 to 5

Organic light-emitting devices were manufactured in substantially the same manner as in Example 1, except that Compounds A to E were used in Comparative Examples 1 to 5, respectively, instead of Compound 3 in forming an emission layer.

Evaluation Example 1

The driving voltage, current density, and maximum quantum efficiency of the organic light-emitting devices manufactured according to Examples 1 to 7 and Comparative Examples 1 to 5 were measured at a current density of 10 mA/cm² so as to evaluate characteristics of the organic light-emitting devices. The driving voltage and the current density of the organic light-emitting device were measured by using a source meter (manufactured by Keithley Instrument, 2400 series), and the maximum quantum efficiency of the organic light-emitting device was measured by an external quantum efficiency measurement device C9920-2-12 (manufactured by Hamamatsu Photonics). In the evaluation of the maximum quantum efficiency, the luminance and current densities were measured by using a luminance meter, of which a wavelength sensitivity was calibrated, and the maximum quantum efficiency was converted based on an angular luminance distribution (Lambertian) assuming a full diffusive reflective surface. Results of evaluating the characteristics of the organic light-emitting devices are shown in Table 2.

TABLE 2 Maximum Host in Driving Current quantum emission voltage Density efficiency Emission Classification layer (V) (mA/cm²) (%) color Example 1 Compound 3 3.6 2.3 18.9 Blue Example 2 Compound 4 3.8 2.3 18.2 Blue Example 3 Compound 8 4.1 2.3 17.3 Blue Example 4 Compound 18 4.5 2.3 20.2 Blue Example 5 Compound 22 3.9 2.3 21.3 Blue Example 6 Compound 53 4.1 2.3 19.1 Blue Example 7 Compound 58 4.3 2.3 21.5 Blue Comparative A 4.6 2.3 13.3 Blue Example 1 Comparative B 4.7 2.3 12.9 Blue Example 2 Comparative C 4.9 2.3 13.1 Blue Example 3 Comparative D 4.3 2.3  8.9 Blue Example 4 Comparative E 5.1 2.3 14.3 Blue Example 5

Referring to Table 2, it can be seen that when Compounds according to one or more embodiments are used as the host material of the emission layer, the driving voltage is lowered and the luminescent efficiency and the maximum quantum efficiency are increased, as compared when the compounds of the Comparative Examples are used as the host.

An organic light-emitting device including the heterocyclic compound according to an embodiment may have a low driving voltage, high luminance, high efficiency, and a long lifespan.

It should be understood that embodiments described herein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each embodiment should typically be considered as available for other similar features or aspects in other embodiments.

It will be understood that, although the terms “first,” “second,” “third,” etc., may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section described above could be termed a second element, component, region, layer or section, without departing from the spirit and scope of the present disclosure.

Spatially relative terms, such as “beneath,” “below,” “lower,” “under,” “above,” “upper,” and the like, may be used herein for ease of explanation to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or in operation, in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” or “under” other elements or features would then be oriented “above” the other elements or features. Thus, the example terms “below” and “under” can encompass both an orientation of above and below. The device may be otherwise oriented (e.g., rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein should be interpreted accordingly.

It will be understood that when an element or layer is referred to as being “on,” “connected to,” or “coupled to” another element or layer, it can be directly on, connected to, or coupled to the other element or layer, or one or more intervening elements or layers may be present. In addition, it will also be understood that when an element or layer is referred to as being “between” two elements or layers, it can be the only element or layer between the two elements or layers, or one or more intervening elements or layers may also be present.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. As used herein, the singular forms “a” and “an” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes,” and “including,” when used in this specification, specify the presence of the stated features, integers, acts, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, acts, operations, elements, components, and/or groups thereof.

As used herein, the terms “substantially,” “about,” and similar terms are used as terms of approximation and not as terms of degree, and are intended to account for the inherent deviations in measured or calculated values that would be recognized by those of ordinary skill in the art. Further, the use of “may” when describing embodiments of the present disclosure refers to “one or more embodiments of the present disclosure.” As used herein, the terms “use,” “using,” and “used” may be considered synonymous with the terms “utilize,” “utilizing,” and “utilized,” respectively. Also, the term “exemplary” is intended to refer to an example or illustration.

Also, any numerical range recited herein is intended to include all subranges of the same numerical precision subsumed within the recited range. For example, a range of “1.0 to 10.0” is intended to include all subranges between (and including) the recited minimum value of 1.0 and the recited maximum value of 10.0, that is, having a minimum value equal to or greater than 1.0 and a maximum value equal to or less than 10.0, such as, for example, 2.4 to 7.6. Any maximum numerical limitation recited herein is intended to include all lower numerical limitations subsumed therein, and any minimum numerical limitation recited in this specification is intended to include all higher numerical limitations subsumed therein. Accordingly, Applicant reserves the right to amend this specification, including the claims, to expressly recite any sub-range subsumed within the ranges expressly recited herein.

While one or more embodiments have been described with reference to the figures, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope as defined by the following claims, and equivalents thereof. 

What is claimed is:
 1. An organic light-emitting device comprising: a first electrode; a second electrode facing the first electrode; an organic layer between the first electrode and the second electrode and comprising an emission layer; and at least one heterocyclic compound represented by Formula 1:

wherein, in Formulae 1 and 2-1 to 2-7, X₁ to X₃ are each independently N or C(R₁₅), wherein at least one selected from X₁ to X₃ is N, L₁ to L₃ are each independently a substituted or unsubstituted C₃-C₆₀ carbocyclic group or a substituted or unsubstituted C₁-C₆₀ heterocyclic group, a1 to a3 are each independently an integer from 0 to 3, Ar₁ to Ar₃ are each independently a group represented by one selected from Formulae 2-1 to 2-7, R₁ to R₁₅ are each independently selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a substituted or unsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₂-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₂-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₂-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —Si(Q₁)(Q₂)(Q₃), —N(Q₁)(Q₂), —B(Q₁)(Q₂), —S(═O)₂(Q₁), and —P(═O)(Q₁)(Q₂), b3 is an integer from 0 to 3, b4 is an integer from 0 to 4, and b5 is an integer from 0 to 5, of the groups included in the heterocyclic compound represented by Formula 1, at least one selected from the substituents R₁ to R₁₁ of the Formulae 2-1 to 2-7 is —Si(Q₁)(Q₂)(Q₃), when Ar₁ is a group represented by Formula 2-7, a1 is 0, when Ar₂ is a group represented by Formula 2-7, a2 is 0, and when Ar₃ is a group represented by Formula 2-7, a3 is 0, when Ar₁ is a group represented by Formula 2-7, Ar₂ and Ar₃ are not a group represented by Formula 2-1 and L₂ and L₃ are not a benzene group, when Ar₂ is a group represented by Formula 2-7, Ar₁ and Ar₃ are not a group represented by Formula 2-1 and L₁ and L₃ are not a benzene group, and when Ar₃ is a group represented by Formula 2-7, Ar₁ and Ar₂ are not a group represented by Formula 2-1 and L₁ and L₂ are not a benzene group, and a case in which each of Ar₁ to Ar₃ is a group represented by Formula 2-1 is excluded, at least one substituent of the substituted C₃-C₆₀ carbocyclic group, the substituted C₁-C₆₀ heterocyclic group, the substituted C₁-C₆₀ alkyl group, the substituted C₂-C₆₀ alkenyl group, the substituted C₂-C₆₀ alkynyl group, the substituted C₁-C₆₀ alkoxy group, the substituted C₃-C₁₀ cycloalkyl group, the substituted C₂-C₁₀ heterocycloalkyl group, the substituted C₃-C₁₀ cycloalkenyl group, the substituted C₂-C₁₀ heterocycloalkenyl group, the substituted C₆-C₆₀ aryl group, the substituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀ arylthio group, the substituted C₂-C₆₀ heteroaryl group, the substituted monovalent non-aromatic condensed polycyclic group, and the substituted monovalent non-aromatic condensed heteropolycyclic group is selected from: deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group; a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁), —S(═O)₂(Q₁₁), and —P(═O)(Q₁₁)(Q₁₂); a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, a biphenyl group, and a terphenyl group; a C₃-C₁₀ cycloalkyl group, a C₁-C₁ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, a biphenyl group, and a terphenyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, a biphenyl group, a terphenyl group, —Si(Q₂₁)(Q₂₂)(Q₂₃), —N(Q₂₁)(Q₂₂), —B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), and —P(═O)(Q₂₁)(Q₂₂); and —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), Q₁ to Q₃, Q₁₁ to Q₁₃, Q₂₁ to Q₂₃, and Q₃₁ to Q₃₃ are each independently selected from: hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryl group substituted with a C₁-C₆₀ alkyl group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, a biphenyl group, and a terphenyl group; and a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryl group substituted with a C₁-C₆₀ alkyl group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, a biphenyl group, and a terphenyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, and —Si(R_(a))(R_(b))(R_(c)), R_(a) to R_(c) are each independently selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a substituted or unsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₂-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₂-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₂-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, and * indicates a binding site to a neighboring atom.
 2. The organic light-emitting device of claim 1, wherein: the emission layer comprises a dopant and a host, the host comprises at least one of the heterocyclic compound, and the dopant is a phosphorescent dopant.
 3. The organic light-emitting device of claim 2, wherein: the dopant comprises platinum (Pt).
 4. The organic light-emitting device of claim 2, wherein: the dopant comprises an organometallic complex represented by Formula 401:

wherein, in Formulae 401 and 402, M is platinum (Pt), L₄₀₁ is selected from ligands represented by Formula 402, and xc1 is 1, 2, or 3, wherein, when xc1 is two or more, two or more L₄₀₁ (s) are identical to or different from each other, L₄₀₂ is an organic ligand, and xc2 is an integer from 0 to 4, wherein, when xc2 is two or more, two or more L₄₀₂(s) are identical to or different from each other, X₄₀₁ to X₄₀₄ are each independently nitrogen or carbon, X₄₀₁ and X₄₀₃ are linked via a single bond or a double bond, and X₄₀₂ and X₄₀₄ are linked via a single bond or a double bond, A₄₀₁ and A₄₀₂ are each independently a C₅-C₆₀ carbocyclic group or a C₁-C₆₀ heterocyclic group, X₄₀₅ is a single bond, *—O—*′, *—S—*′, *—C(═O)—*′, *—N(Q₄₁₁)-*′, *—C(Q₄₁₁)(Q₄₁₂)-*′, *—C(Ω₄₁₁)═C(Q₄₁₂)-*′, *—C(Q₄₁₁)=*′, or *═C(Q₄₁₁)=*′, wherein Q₄₁₁ and Q₄₁₂ are each independently hydrogen, deuterium, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, or a naphthyl group, X₄₀₆ is a single bond, O, or S, R₄₀₁ and R₄₀₂ are each independently selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a substituted or unsubstituted C₁-C₂₀ alkyl group, a substituted or unsubstituted C₁-C₂₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₁-C₁ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₁-C₁ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —Si(Q₄₀₁)(Q₄₀₂)(Q₄₀₃), —N(Q₄₀₁)(Q₄₀₂), —B(Q₄₀₁)(Q₄₀₂), —C(═O)(Q₄₀₁), —S(═O)₂(Q₄₀₁), and —P(═O)(Q₄₀₁)(Q₄₀₂), wherein Q₄₀₁ to Q₄₀₃ are each independently selected from a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a C₆-C₂₀ aryl group, and a C₁-C₂₀ heteroaryl group, xc11 and xc12 are each independently an integer from 0 to 10, and * and *′ in Formula 402 each indicate a binding site to M in Formula
 401. 5. The organic light-emitting device of claim 4, wherein: A₄₀₁ is C₁-C₆₀ heterocyclic group containing at least one nitrogen.
 6. The organic light-emitting device of claim 4, wherein: X₄₀₅ and X₄₀₆ are each a single bond.
 7. The organic light-emitting device of claim 4, wherein: R₄₀₁ is not a hydrogen.
 8. A heterocyclic compound represented by Formula 1:

wherein, in Formulae 1 and 2-1 to 2-7, X₁ to X₃ are each independently N or C(R₁₅), wherein at least one selected from X₁ to X₃ is N, L₁ to L₃ are each independently a substituted or unsubstituted C₃-C₆₀ carbocyclic group or a substituted or unsubstituted C₁-C₆₀ heterocyclic group, a1 to a3 are each independently an integer from 0 to 3, Ar₁ to Ar₃ are each independently a group represented by one selected from Formulae 2-1 to 2-7, R₁ to R₁₅ are each independently selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a substituted or unsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₂-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₂-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₂-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —Si(Q₁)(Q₂)(Q₃), —N(Q₁)(Q₂), —B(Q₁)(Q₂), —S(═O)₂(Q₁), and —P(═O)(Q₁)(Q₂), b3 is an integer from 0 to 3, b4 is an integer from 0 to 4, and b5 is an integer from 0 to 5, of the groups included in the heterocyclic compound represented by Formula 1, at least one selected from the substituents R₁ to R₁₁ of the Formulae 2-1 to 2-7 is —Si(Q₁)(Q₂)(Q₃), when Ar₁ is a group represented by Formula 2-7, a1 is 0, when Ar₂ is a group represented by Formula 2-7, a2 is 0, and when Ar₃ is a group represented by Formula 2-7, a3 is 0, when Ar₁ is a group represented by Formula 2-7, Ar₂ and Ar₃ are not a group represented by Formula 2-1 and L₂ and L₃ are not a benzene group, when Ar₂ is a group represented by Formula 2-7, Ar₁ and Ar₃ are not a group represented by Formula 2-1 and L₁ and L₃ are not a benzene group, and when Ar₃ is a group represented by Formula 2-7, Ar₁ and Ar₂ are not a group represented by Formula 2-1 and L₁ and L₂ are not a benzene group, and a case in which each of Ar₁ to Ar₃ is a group represented by Formula 2-1 is excluded, at least one substituent of the substituted C₃-C₆₀ carbocyclic group, the substituted C₁-C₆₀ heterocyclic group, the substituted C₁-C₆₀ alkyl group, the substituted C₂-C₆₀ alkenyl group, the substituted C₂-C₆₀ alkynyl group, the substituted C₁-C₆₀ alkoxy group, the substituted C₃-C₁₀ cycloalkyl group, the substituted C₂-C₁₀ heterocycloalkyl group, the substituted C₃-C₁₀ cycloalkenyl group, the substituted C₂-C₁₀ heterocycloalkenyl group, the substituted C₆-C₆₀ aryl group, the substituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀ arylthio group, the substituted C₂-C₆₀ heteroaryl group, the substituted monovalent non-aromatic condensed polycyclic group, and the substituted monovalent non-aromatic condensed heteropolycyclic group is selected from: deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group; a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁), —S(═O)₂(Q₁₁), and —P(═O)(Q₁₁)(Q₁₂); a C₃-C₁₀ cycloalkyl group, a C₁-C₁ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, a biphenyl group, and a terphenyl group; a C₃-C₁₀ cycloalkyl group, a C₁-C₁ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, a biphenyl group, and a terphenyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₂₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, a biphenyl group, a terphenyl group, —Si(Q₂₁)(Q₂₂)(Q₂₃), —N(Q₂₁)(Q₂₂), —B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), and —P(═O)(Q₂₁)(Q₂₂); and —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), Q₁ to Q₃, Q₁₁ to Q₁₃, Q₂₁ to Q₂₃, and Q₃₁ to Q₃₃ are each independently selected from: hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryl group substituted with a C₁-C₆₀ alkyl group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, a biphenyl group, and a terphenyl group; and a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryl group substituted with a C₁-C₆₀ alkyl group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, a biphenyl group, and a terphenyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, and —Si(R_(a))(R_(b))(R_(c)), R_(a) to R_(c) are each independently selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a substituted or unsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₂-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₂-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₂-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, and * indicates a binding site to a neighboring atom.
 9. The heterocyclic compound of claim 8, wherein: at least one selected from Ar₁ to Ar₃ is a group that is different from the others thereof.
 10. The heterocyclic compound of claim 8, wherein: i) Ar₁ and Ar₂ are each a group represented by Formula 2-1, and Ar₃ is a group represented by Formula 2-3; ii) Ar₁ is a group represented by Formula 2-1, and Ar₂ and Ar₃ are each a group represented by Formula 2-3; iii) Ar₁ is a group represented by Formula 2-1, Ar₂ is a group represented by Formula 2-3, and Ar₃ is a group represented by Formula 2-4; iv) Ar₁ is a group represented by Formula 2-1, Ar₂ is a group represented by Formula 2-3, and Ar₃ is a group represented by Formula 2-3; v) Ar₁ is a group represented by Formula 2-1, and Ar₂ and Ar₃ are each a group represented by Formula 2-4; or vi) Ar₁ and Ar₂ are each a group represented by Formula 2-3, and Ar₃ is a group represented by Formula 2-6.
 11. The heterocyclic compound of claim 8, wherein: i) when Ar₁ is a group represented by Formula 2-1, at least one selected from R₁(s) in the number of b5 is —Si(Q₁)(Q₂)(Q₃), and ii) when Ar₁ and Ar₂ are each a group represented by Formula 2-3 and Ar₃ is a group represented by Formula 2-6, at least one selected from R₁₀(s) in the number of b4 and R₁₁(s) in the number of b3 is —Si(Q₁)(Q₂)(Q₃).
 12. The heterocyclic compound of claim 11, wherein: at least one of Q₁ to Q₃ comprises at least one deuterium.
 13. The heterocyclic compound of claim 8, wherein: Ar₁ to Ar₃ are each independently a group represented by one selected from Formulae 2-1(1) to 2-1(3), 2-2(1) to 2-2(2), 2-3(1) to 2-3(2), 2-4(1) to 2-4(2), and 2-6(1) to 2-6(4):

wherein, in Formulae 2-1(1) to 2-1(3), 2-2(1) to 2-2(2), 2-3(1) to 2-3(2), 2-4(1) to 2-4(2), and 2-6(1) to 2-6(4), Z₁₁ to Z₁₅ are each independently selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bitluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a silolyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a benzofuranyl group, a benzothiophenyl group, a benzosilolyl group, a dibenzosilolyl group, and —Si(Q₃₁)(Q₃₂)(Q₃₃), Q₃₁ to Q₃₃ are each independently selected from a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, and a pyridinyl group, e3 is an integer from 0 to 3, e4 is an integer from 0 to 4, e5 is an integer from 0 to 5, Ph indicates a phenyl group, and * and *′ each indicate a binding site to a neighboring atom.
 14. The heterocyclic compound of claim 13, wherein: 1) Ar₁ is a group represented by Formula 2-1(1), and Z₁₁ in Formula 2-1(1) is deuterium; 2) Ar₁ is a group represented by one selected from Formulae 2-1(2) and 2-1(3), and i) Z₁₁ in Formulae 2-1(2) and 2-1(3) is deuterium; ii) Z₁₂ in Formulae 2-1(2) and 2-1(3) is selected from deuterium and a benzene group substituted with deuterium; iii) Z₁₂ and Z₁₃ in Formulae 2-1(2) and 2-1(3) are each independently selected from deuterium and a benzene group substituted with deuterium; or iv) Z₁₁ to Z₁₄ in Formulae 2-1(2) and 2-1(3) are each independently selected from deuterium and a benzene group substituted with deuterium; 3) Ar₂ is a group represented by Formula 2-3(1), and i) Z₁₁ in Formula 2-3(1) is deuterium; or ii) Z₁₁ and Z₁₂ in Formula 2-3(1) are each deuterium; or 4) Ar₂ is a group represented by Formula 2-3(2), and i) Z₁₁ in Formulae 2-1(2) and 2-1(3) is deuterium; ii) Z₁₂ in Formulae 2-1(2) and 2-1(3) is selected from deuterium and a benzene group substituted with deuterium; iii) Z₁₂ and Z₁₃ in Formulae 2-1(2) and 2-1(3) are each independently selected from deuterium and a benzene group substituted with deuterium; or iv) Z₁₁ to Z₁₄ in Formulae 2-1(2) and 2-1(3) are each independently selected from deuterium and a benzene group substituted with deuterium.
 15. The heterocyclic compound of claim 13, wherein: at least one selected from Ar₁ to Ar₃ is a group represented by one selected from Formulae 2-1(2), 2-1(3), 2-2(2), 2-3(2), 2-6(3), and 2-6(4).
 16. The heterocyclic compound of claim 8, wherein: i) X₁ to X₃ are each N; ii) X₁ and X₂ are each N, and X₃ is C(R₁₅); iii) X₁ and X₃ are each N, and X₂ is C(R₁₅); iv) X₂ and X₃ are each N, and X₁ is C(R₁₅); v) X₁ is N, and X₂ and X₃ are each C(R₁₅); vi) X₂ is N, and X₁ and X₃ are each C(R₁₅); or vii) X₃ is N, and X₁ and X₂ are each C(R₁₅), and R₁₅ is hydrogen or deuterium.
 17. The heterocyclic compound of claim 8, wherein: at least one hydrogen atom in the heterocyclic compound represented by Formula 1 is substituted by a deuterium atom.
 18. The heterocyclic compound of claim 8, wherein: at least one of R₁ to R₁₅ in Formulae 2-1 to 2-7 comprises deuterium.
 19. The heterocyclic compound of claim 8, wherein: at least one of R₁ to R₁₅ is selected from: deuterium; a C₁-C₆₀ alkyl group, and a C₆-C₆₀ aryl group substituted with at least one deuterium; and —Si(Q₁)(Q₂)(Q₃); and wherein, Q₁ is selected from a phenyl group and a biphenyl group substituted with at least one deuterium, and Q₂ and Q₃ are each independently selected from a phenyl group; a biphenyl group; a phenyl group and a biphenyl group substituted with at least one deuterium.
 20. The heterocyclic compound of claim 8, wherein: i) R₁ is selected from deuterium; a phenyl group substituted with at least one deuterium; and —Si(Q₁)(Q₂)(Q₃); ii) R₄ and R₅ are each independently selected from deuterium; a phenyl group substituted with at least one deuterium; and —Si(Q₁)(Q₂)(Q₃); iii) R₆ and R₇ are each independently selected from deuterium; a phenyl group substituted with at least one deuterium; and —Si(Q₁)(Q₂)(Q₃); iv) R₁₀ and R₁₁ are each independently selected from deuterium; a phenyl group substituted with at least one deuterium; and —Si(Q₁)(Q₂)(Q₃); or v) R₁₂ to R₁₄ are each independently selected from deuterium; a phenyl group substituted with at least one deuterium; and —Si(Q₁)(Q₂)(Q₃); wherein, Q₁ is selected from a phenyl group and a biphenyl group substituted with at least one deuterium, and Q₂ and Q₃ are each independently selected from a phenyl group; a biphenyl group; a phenyl group and a biphenyl group substituted with at least one deuterium. 